Does a carburetor cost a lot to fix?

Probably more than the Jeep is worth. And that's just the beginning.

The previous answer is so right about that it is probably just the beginning. Not more than your waggy is worth though. Have your mechanic buy the carb (or your buy it and have it sent to them) from www.teamgrandwagoneer.com. There is a discount code from the FB page "saving jeep grand wagoneers" and also probably "wagoneers in the spotlight" but I don't have it on me right now. It should be around $500-$600 total, the carb is approx. $200, but you can get $50 if you send back your old one. I kept mine, just incase, but most people trade theirs in. I'll write back if I find the discount code today. Good luck!