If you want a fountain pen like that (as opposed to a dip pen†), the only non-insanely-expensive source I've found is old pens with gold nibs ... If it's something not particularly attractive (there are lots of dull black old pens around), the price can be vastly more tractable than modern high-quality fountain pens.

Unfortunately the basic market for high-quality new pens seems to be as a luxury accessory, with price inflation to match. There's an apparent increase in low-priced new fountain pens in the last few years, but they all seem to have extremely stiff nibs made of thick steel or something.

[I met a guy in Boston who had a small open-by-appointment shop with like 4-5000 old fountain pens, most of which were not really pretty enough to sell well as boutique/antique items, but many of which wrote very nicely. He bought a lot of pens and eeked out a living selling the prettier ones; I'm not really sure what the eventual fate of the rest is.]

† There are tons of super cheap and nice flexible nibs available for dip pens, though I guess many are not well suited to general writing.