Dear Mike,
Since you posted this in the Cross forum, I can point out that Cross offers two lines well within your price range that are high quality pens including fountain pen, rollerball and ballpoint choices, the Townsend and the Apogee. Cross has lots of dealers, so you should have no trouble locating a pen at a good price.

Cross Apogee Frosty Steel Fountain Pen

Cross Townsend Garnet Selectip Pen
The pens are about the same length and weight, with the Apogee being very modern looking and the Townsend being very classic, with cues from the original Cross Century from the 1940s.
Cross pens all write well, and their refills are very easy to find, so giving one will not put your dad in a position of having something that he can't get supplies for.
What I recommend, since you asked very generally, is to think about whether your dad likes classic / vintage items or up to date modern? Does he use a fountain pen now, or is he most likely to use a ballpoint or rollerball. I would recommend you give him a pen he will want to use, not a paperweight that will sit in the box.
Best of luck with your decision!
Cheers,
Jim Mamoulides
www.PenHero.com