Mountain Biking - Schwinn Sierra MTB -- worth it?

Greetings, folks. Please excuse a n00b question on your sub-forum -- I hang out on road cycling sub-forum mainly.

But I've been toying with getting a cheap used hard-tail MTB, for a few reasons: 1) fun; 2) something to ride on trails when it's crappy winter weather on the roads; and 3) to pick up some technical skills to apply to my road riding. I have nearly zero extra $. A friend of mine is selling a vintage Schwinn Sierra MTB, in somewhat decent shape. He bought it used years ago for $75. He doesn't use it at all.

Is it worth it, even at a dinky price? Does it have more value as a vintage piece than as a bike to ride? It's heavy as a tank (I'm guessing pure steel frame.) Would I be able to enjoy riding it? What would you pay?

If there's a better place to post this, let me know. And thanks!

I have an old Sierra in black chrome finish. It is a very nice all round riding bike with slicks. The one I have is double butted cro-moly, so it is a sturdy and durable machine. If I had the opportunity to pick up another one for cheap I would be on it in a second.

is it mechanically sound?

no rust?

good tires?

if so, fitty dorra and a six pack of favorite beer (theirs, not yours)

Awesome, guys -- thanks for the insight. If it turns out to be mechanically and structurally sound, do you think I could learn some beginner's mountain biking stuff on it? Would I be sneered at by those in the know for the age and low pedigree of my bike? Or maybe it has some caché because it's older...

I'd prob. have to ride in sneakers using the toe clips, 'cause right now I don't have the scratch for another pair of clipless pedals and a new pair of shoes. So that really answers the question about being laughed at... But maybe it would at least reveal whether I want to save up for a newer bike later on.

It'll get you riding! Go have fun!

Think about it this way. That bike set-up is what the Pro's were using (and having a blast on) in the 80's. Worked for them, it'll work for you!

tell them your old school.

It's lack of suspension might rattle your bones...

People with no appreciation for a vintage MTB will laugh, but who cares...

it will punish you on the trails.

Thanks, folks -- I think I will stop by my friend's place and give the bike a real once-over with the hope of buying it. I've only glanced at it, but I think it's in decent shape. I appreciate the encouragement. And the warnings. (I'm sure it will rattle my bones, but since there's no other way I'm getting a MTB anytime soon, I guess bone-rattling fun is better than none!)

don't worry bout the rigid. you'll be sore after the first couple of rides, but if you ride it regularly, your body will get used to it.

There are no bad bikes except for unridden ones.

Thanks again for the encouragement, guys. I read somewhere that hard-tail is the way to start with MTBs, and it felt right to me when I read it, so here goes. Seems like it would be hard to get in the door for a cheaper price!