Please treat this just as my opinion. My apologies if i annoy / offend any one sorry.
If you are after a good deal my recommendation is to avoid ebay and most of the online shops. Either go to local antique fairs or regional auction sites specific to your country. You are likely to get much better deal. Current situation around the world isn't going to be good for antique fairs so next best thing would be local auction sites.
I am not going to link to any running auctions in order to comply with policies. This is the last closed auction i can see in an auction local to my area. Who ever won it got 5 pens for around $83 US, (Site is showing on NZD).
Most deals are not that great but you can consistently get 51s for around 50$-85$ mark. Upper being r.silvers or 12ks.
However there is an obvious drawback. you are basically buying as it is. If you go with a reputable dealer you will pay a little extra, but you will end up with a product that's in good order. And some one to back it up if something goes wrong. This is a better option in the long run, shipping a pen to repair added in to the cheap deal may not be cheaper at all.
If you can repair the pen your self or know some one that can, then cheap option is good. If you are in a middle of nowhere (like me ) and have to ship pens to either the US or Europe to get repaired, then the answer is obvious.
Reuploaded the image removing user ids .
Edited by shalitha33, 17 August 2020 - 12:15.