How much would it roughley cost for a mazda mx3 1.8 v6 engine reconditioning?

The Mazda MX3 GS is a rare find in general. That engine was only offered from 1992-1995 I believe and in limited numbers. Your best bet is to find a low mileage used engine from Japan. They may not cost too much since it is a small displacement engine. One place you can try is cnsmotors.com. I have had good experiences with them in the past. they have two shops here in S. California and they do ship online stuff as well. It still might be cheaper than getting yours rebuilt. Also, these engines have around 30,000-35,000 miles on them since Japan has very strict smog laws meaning preople are getting rid of their engines around 50,000 kms.  more