Don't test me.I'd like to see you make this post using your fountain pen...
Joking aside I love fountain pens. I used to use them for ink sketching a few years back. I didn't get anything fancy thou cause I would destroy them in a few days from new due to extreme pressure I'd apply for artistic effects. I used to get plain fountain pens with wooden base that you'd have to dip in an ink bottle. They were cheap too, like 10Euro for a set of 4 or something like that. Then I got a graphics tablet and they faded out of existence for me.
Also they were awesome to write Tengwar with...
Dip nibs go for pretty cheap, which makes them good for doing custom grinds. There are nibs made for flexing that don't take a ton of pressure to get line variation from. I have a graphics tablet, myself, but for writing it just isn't the same.
I actually used Tengwar script before I constructed my own. It's very nice looking.