When you get the bike home, try inflating the tires. If they hold air, check to see if the tire tread and sidewalls exhibit any dryness and cracking. If the inner tubes hold air and the tires look good you will have saved a fair bit of money at zero cost
Getting the bike back into ridable condition should be the goal, not updating it. This looks like a pretty good quality bike, and it certainly doesn't look "far gone" at all. It needs work, but most of the work needed has no cost involved. If the tires hold air, all it may need so that you will be able to ride it would be a new chain, plus a full overhaul and cleaning