For a beginner, and a student beginner especially, the largest consideration is price. I have had all the pens mentioned (except the Al-Star and the Loom, but have borrowed both multiple times from friends) and they are all good pens. Even the Petit1 is a good pen! For "credentials", I have convinced more than two dozen people the past year to buy their first fountain pen. As far as I know they all still use the pens. Hashtag penvangelism.
My default answer to people who want to buy their first pen is the Pilot Metropolitan. Why? A lot of people (especially at my age; '90s kid) are used to ballpoints and gel pens. I know exactly one person in my life who uses a rollerball pen. This means most people are used to thin line widths which, in my experience, only the Pilot Metropolitan <F> can offer. I've used the EF nib of Lamy and TWSBI and both are demonstrably thicker than a Pilot Fine.
The logic behind suggesting a pen within the prospective convert's comfort zone is that you don't just want to suggest a good pen to someone, you want the person to keep using that pen and abandoning the use of non-fountain pens. Easing them into it helps.
Back to price. In my country, a Safari is three times more expensive than a Metro. The Safari does not come with a converter. Even if you want to switch to a Con-50 or Con-40, the Safari is still more than twice as expensive—I hate it). In my country as well, the Eco (about $40.00 here) is two dollars away from being four times as expensive as a Metro. This is a huge difference because even if we "sell" fountain pens as being built to last, most first-time buyers are perfectly fine using a $1 Pilot G-tec. They absolutely love the G-tec. A Metropolitan is fifteen G-tecs. To stretch the comparison a bit, a Porsche 911 is just five Toyota Corollas.
A super budget pen would be a Preppy, a Petit1, or a V-Pen. The cap of the Preppy breaks with regular cautious use and a Petit1's clip will break-off. A V-Pen is too cumbersome to refill unless you have one where the feed can be pulled-off (mine can't, even with pliers).
Now, why would you not buy a Pilot Metropolitan? Besides an uncommon problem of some people reporting that it ejects ink into the cap for no reason, the most obvious are the large step and the design. For quite some time, I didn't get a Metropolitan because the design didn't speak to me. They wrote well enough but not well enough for me to get over the weird middle band. I just couldn't understand why the background of the middle band was different in shade to the the rest of the pen (in MR1), and later on the animal bands just horrified me (in MR2). Eventually I got used to the design and I have three of them right now (I've owned five in total). Then there's the step. From all the pens mentioned this has the largest step. I understand why the step is there but I still prefer a pen that is streamline uncapped versus a pen that is streamline while capped. I look at pens when they are ready to use, not when they are to be kept in storage. I have since been able to modify my grip when using this and similar pens such that they are no more uncomfortable than other pens (my fingers sort of cling to the ledge of the step).
Now, why would you get a Safari instead? While the nib width and quality control is a bit of a lottery and the inner cap does tend to break down, both problems are easily dealt with. The biggest draws for me is the easy exchange-ability of nibs matched only by Kaweco among current pens. Of course, depending on the market a Lamy nib costs more than a Metro... The section/grip of the Safari is also talked about a lot. It really depends on your grip and it's important that you be able to borrow a pen first before you buy it. There are also people who buy the pen after trying it in the store and then sell it a week later because it's too big or too heavy but these are unusual people. For me, the Safari is easier to hold than a Metro even if I don't hold pens the way Lamy wants me too (only one of my fingers is "where it's supposed to be").
Why don't you get an Eco? The grip is the easiest to use and the capacity will not leave you wanting. To me, the largest barrier is again the price. You must be a great fan of the demonstrator look and the piston capacity if you want this pen where I live. I see that in the US it is the same price as a Safari so that is not a consideration for you, of course. I do like the screw cap (I wish all pens were screw caps) but if you post your pens this has the worst posting experience among all of the pens mentioned. I'm sure it's secure but it doesn't inspire you about its security. I also think it looks the worse among all the pens. I actually like how the Preppy looks more than an Eco. The all clear version looks really greats though, up until you ink it and ink inevitable gets on and behind the inner cap...
The Eco performs at a comparable rate to the Safari (again, I think they all write well albeit slightly differently) and it may come down to personal preferences. Do you value nib-swapping more than a piston's capacity? Do you prefer a screw cap to a snap cap? If you want to experiment with unusual inks you may be better off staying away from the Eco. There's too much worrying involved in keeping the barrel pristine.
Is anyone still reading?
Alright, a Kaweco Sport is alright and I really like the look. Besides the possibility of a poor nib (happens to all manufacturers anyway), you have to be open to dealing with unavoidable barrel wear. Unavoidable! You also need to post the pen to write with it. Another thing is that if you want to use cartridges on a transparent Kaweco you should know beforehand that it looks pretty lame. A lot of people complain about proprietary cartridges and there was a recent post here about someone making a permanent international cartridge; Kaweco needs to make a proprietary cartridge that fills the length of the Kaweco barrel. Short international cartridges look terrible!
A Loom is great and I really want to buy one save for two worries. First, the cap looks really bad and there is something off in the way it clicks shut. It is the pit of cap-shutting feel, at the opposite end of the Prera. Another is that it there is a risk of parts incompatibility. It's standard international but not all cartridges and converters work on it. A friend bought a Faber-Castell converter from the same store and it didn't fit..
The Prera is great but do you want to pay that much more for a the same writing end as a Metropolitan. You also need to post the pen to be able to write with it. If you're Kawhi Leonard don't even consider it.
For the less mentioned pens a Parker IM I think is the most expensive mentioned here. I have one. The clear coat has come off in spots and it's very ugly because of it. I think it's a good review pen because it's so easy to clean even if you can't remove the nib or the section. I would not recommend it. It's a $10 value to me. I also have a Parker 45 and it's good, smooth, and easy to disassemble. I think it's also the one with the most "character" among all the pens. I would caution you as to nib width though. I bought an NOS "45" that had a fine nib and wrote as thick as my Medium Safari. Very smooth writer but it needs an IG ink to be at a width I can use with. Otherwise I can only use it to underline my readings.