Fountain pens appeal to a certain sort of person (like myself). Rather than picking up an inexpensive and disposable ball point pen, you are using a finely crafted instrument that can last almost forever. You have the opportunity to select what ink you fill the pen with.
Inexpensive pens. You can get a great pen for under $50. A famous recommendation is the Lamy Safari for about $25. There are a multitude of well priced pens from China (Jinhao, Asvine) in this price range that can be very good.
More expensive pens. These are pens under $200, sometimes under $100. This is where I find my favorites. My all time favorite is the Sailor Pro Gear (or the Platinum 3776, or the Pilot Custom 74). These all used to be available for $150 or so, but recently prices for those with gold nibs have skyrocketed to $350 in some cases.
Expensive pens. You are now moving into the realm of "male jewelry". It is not clear that any of these write better than a good Sailor, but they often look better and are made from nicer materials. Here you have pens that sell for over $500. The Visconti Homo Sapiens is an example, selling for $800.
Status pens. These are pens that sell for over $1000. The Montblanc 149 is the poster child here, selling for $1270. I could be wrong, but I am skeptical that these perform better than more sensibly priced pens.
Tom's Pen Info / tom@mmto.org