There are many factors to consider when replacing a bridge on a banjo. What style of banjo-playing do you do? For example, clawhammer/frailing players typically prefer higher action, which could be accommodated by a tall bridge. There are different styles of bridges (moon compensated, etc.) to look at. There are bridges with bigger feet that put more mass against the banjo head, there are maple bridges with ebony tops or some other substance (mine is corian). Then, of course, some are inexpensive ($3 - $6 US) and some are expensive ($13 - $30 US) (I'm scanning the most current Elderly Instruments catalog for these prices).

My point is, order a number of inexpensive bridges at different heights and styles and you decide which one you like best, changing them yourself. Or call your music store and ask if you could bring your banjo in and try-on different ones while in the store before making a decision...

Hope this helps...
-Greg