'90 735il transmission dead???

[shogun]

500$ including installation as max budget: I would clearly tell the customer, forget it. Whatever you try, 500 is low anyway if you do it as a business, and no one is sure if the first trial to repair it is in fact the repair necessary, I would go for the $1200 735, and keep the other one as parts car. But of course he needs space and willingness for DIY.

[Ross]

I agree with Shogun. $500 won't cut it. Even a fast R&R guy is going to need 2-3 hrs, plus fluid, exhaust hangers, misc broken fasteners, futzing with corroded cooler lines.
Time to retire this 7.