Actually, Gli and Trx prices can be so varied its not funny. I payed a trx price for my gli ($3500), and ive seen people pay half that for a trx. But it depends on condition and where you go. My car was immaculate, and from a dealer, so i had no worries whatsoever in paying it.
And CA20DET is no easy task, i can vouch for that. You need a LOT of money and a LOT of luck to get it done. Ive spent easily over a grand in shit i dont need/cant use because its hard to find ca engine parts.
Good luck with the Gli. Get some pics up and hopefully see you on a cruise soon ey?