The car might be a candidate for a good used motor. You could expect to pay only several hundred dollars for such a motor because they don't often fail.

I bought an '82 B21 motor with 70k miles for $100.

I bought a '91 B230F *with* the AW71L tranny, 140k miles, for $100.

I'd plan $400-700 to drop in a good motor -- and it's something a shadetree mechanic can do himself (herself?).

If you do search out a good used motor, be sure to perform basic maintenance items on it before installing, such as a new rear main seal. The seal is cheap, and it's easy to install with the motor out but it's a bear of a job with the motor in.

Repairing the existing motor is likely to cost more than buying a used motor.

Buy carefully.
--
Don Foster (near Cape Cod, MA)