First off, if the car was over a quart low, it makes me wonder how many miles the car has been running with such a low oil level. That's going to definitely have a detrimental effect on any car, but in particular on a car with already fairly high mileage. When was the last time you checked it (miles)? Is it often low when you check it? Oil is there not only to lubricate, but also to cool. When it's missing a third or more of its fluid, both of those things are severely impacted, so you've been putting heavy strain on the engine before you ever took it to the track. It sounds like that was just the final straw in a long lead up to kablooey.
NADA puts the clean retail value at $9,150. Given the mileage, I'd say it's highly unlikely the car is really in that condition and probably merits more of a good or very good rating, which puts the value in the low $8k range. A new motor and labor is going to cost $6k, which would bring the value down to $2k using simple math. However, you can't use simple math in this situation and need to account for the lack of an engine with dollars too for the headache, which means take another grand off. That puts the value at $1,000-$1,500. Honestly if I were you I'd be parting the thing out and getting something else. It's not worth it to replace the motor in a car with so many miles and such a low value.
It might just be your lucky day. Just noticed somebody posted this:
Motor for sale