I generally advocate this approach, but the OP made it sound like his not mechanically inclined, and though capable of doing simple work (adjusting brakes) he isn't interested in doing it if he doesn't need to.

Around here that bike would probably go for $60 on Craigslist.
For $60 you could also get a rigid '90s mountain bike that was worth putting money into.

If you're going to do the work yourself, do (just) the needed repairs. If it would be a matter of paying a shop to do the work I'd still say it depends on the details of the bike as to whether it's worth it.

Then again this is coming from a guy who upgraded a DiamondBack Wildwood with a new fork (and headset), stem, handlebars, shifters, wheels, and pedals (if I can just put a decent RD on I'll be really happy with it). I'm big on doing the work myself, but we each decide if that's right for us.

If you do decide to fix this bike up, for anything beyond pads and cables donor bikes are a wonderful thing.