I feel your pain. My car just got out of the shop, having cost a similar amount for very different repairs. Both steering column u-joints plus 4 'fan' belts plus a new splash pan. Still beats regular car payments of nearly the same amount. Some work I do myself, some I have done by others.

Any time I read "oil leak" I immediately think "flame trap".

Not to say that your rear main seal doesn't need replacing. If it's leaking that badly, I'd guess it really does need a new seal. But you, or someone, should go through the whole flame trap/crankcase ventilation system to make sure it's clear, unless you already know it's clear. Any blockage there will have the car leaking oil again soon.

See the FAQ, section on "Engine belts, seals, and crankcase ventilation", and follow it to the plentiful information on the flame trap system.
--
Sven: '89 245, IPD sways, electric rad. fan conversion, 28+ mpg - auto tranny. 850 mi/week commute. '89 245 #2 (wifemobile). '90 244 (spare, runs).