I'm looking for a pen with line variation that I can use for taking notes.I want it to write fine and preferably not very wet I have a small budget ~$35. The only pens I've seen that I've seen that fit the criteria are Noodler's Ahab/Konrad, Nemosine Singularity and Pilot Plumix, which of these would be the best for note taking and are there any other pens that fit the criteria.
Andr, as stated above, of these, only the Noodler's pen allows flex. I've never used either model. I don't know how fine the nib writes when not flexing, and I've read that it's pretty stiff, requiring a lot of pressure to flex.
Nemosine Singularity (optionally) and Pilot Plumix both come with stub nibs, and the "line variation" is not the same as flex line variation, and with a stub, you have no choice of whether to have line variation or not - it's always skinny one way and fat the other. With a flex nib, you can always choose not to flex it, thus getting a finer line. So, whether either of these would do something you enjoy really depends on what you mean by "write fine". The Nemosine .6mm stub will certainly write small, but I wouldn't exactly call it fine. I'm an EF person, but I do really enjoy the .6 stub, FWIW, but I don't think I'd want it as my only note-taker.
I fear what you really want is a Pilot Falcon SEF or SF, but that's well outside your budget.