Hard to say, depends on who's buying.
A year and half ago I bought a 1992 LS-L with 47K for $2000. It has a some issues, mainly a busted wheel bearing and a cracked radiator. It does have a rebuild transmission (with just a few 1000 miles on it). It also needs it's major service (original timing belt, water pump, etc.) and new tires.
I figure if I sorted everything, I would easily sell it for $5K. If was willing to wait and hold out for the buyer, I could maybe get close to $8K-10K. Of course, I'm going to keep it and drive it.
There is also a "craigslist finds" thread which lists a few low mileage examples:
http://www.subaru-svx.net/forum/showthread.php?t=64730
(with low mileage ones going for $6K to $12K IIRC)
Somebody recently said they where going to list their SVX on BaT. Maybe wait and see how that does to get an idea of that they will go for. Here is the completed listings for what the SVX sold for on BaT. Just type in SVX in the search box.
https://bringatrailer.com/auctions/results/
Good luck,
Ian.