Hi - Sorry for your loss.
Your motor looks like an import turbo wagon, prices for subaru's these days seem to be all over the place. You could advertise on Facebook groups, (There are groups for barn finds and specific subaru cars) it does look as though it will need going over / recommissioning but will make a nice project for someone. Knowing if it starts / runs will help but if not it means someone will need to trailer the motor away.
I would look to members who are more experienced on the classic motors for a price - I would guess at £1500 due to the unknowns but it could be a £3000 car if there is no rust on the rear arches, the motor runs and it can be driven