Unfortunately, powder coating prices can be all over the map. I've heard from guys who've said that a powder coating shop quoted them over $300 to strip and 'coat a frame.
I think that's ridiculous.
Then again, I'll bet that shop doesn't do many bicycles and can't see 'em as a profit generator.
The shop I work with has done two frame/fork jobs for me. Both needed stripped, one a little and one (my Goat/Big Dummy) a LOT. Prices for those two jobs were approximately $100 and $200, with the Goat being the higher-priced job.
They like doing frames/forks: lots of bicycle samples are hanging on the walls. And they're nice people, too.
Worth it? Well, it is to me. I've heard mixed reviews about factory paint and powder coats and I'm a somewhat picky, artsy-fartsy dude, so it's worth it to me as a longer term investment on two levels:
1. I know the quality and reputation of my local powder coater's work, and
2. I also enjoy the blessing of a personalized color choice. I get to make it 'mine'.
All this is unnecessary, of course, in the big picture. But, if you can afford the Kool-Aid...
Just one guy's opinion.