Is this bike worth $100? (26inch wheels)

Yes.

Looks like a 20in or large. Expect it to need a tune up

Yep..all day long. These days it'll go for more than that if in good condition. Very nice bike. Looks like a 1991 model in a 20 inch frame. Great starting point for a drop bar conversion also. (My touring bike is a drop bar converted 970). If you're looking for a all-rounder bike, put some street tires on it (Maxxis DTH, Schwalbe Big Bens..) on it.

If it fits you and doesn't require a lot of money to be put into it to make it rideable, sure. I suppose it depends on what you want to use it for too.

Not bad at $100, not great though. If the wheels are true, and the drivechain condition is not worn out.

I think those cleaned up and working at $300 in local sale value. I had a 930 very similar that I sold for $375 completely rebuilt 3x9, but that was in the covid buyer binge. Things have cooled some.

No, its not worth $100. Its worth more like $175. Lugged rigid frame MTB, one of the better ones.

This is the kind of MTB I recommend almost daily. Rigid frame, with higher end components.

Night and day better than that 800 you posted recently. No comparison really. The "deals" out there on old MTBs are the high end ones. Most buyers are looking for name brand at a low price and don't know the difference between the really good ones and the lower end ones. Get knowledge or get taken.

If it in my area, I would be loading it up right now.

Like any 30 year old bike, you should expect it to need thorough maintenance. If you can do the maintenance, great. If not, stop looking at vintage bikes as the "thorough" maintenance can cost around $250 at a local bike shop here, PLUS parts. Very easy to end up upside down.

Nice bike. Deore LX. If you are looking for an all around bike this would fit the bill. Semi collectible so you better get in contact fairly quick

I would be ecstatic to find one in that size for $100 around here. I foolishly parted with my c.1990 950 and have kicked myself for quite a while since. Ideal for dropped-bar conversion!

I would go get it now as others have said this is a very nice bike for the price. With a few minor upgrades replacement of wear parts brake pads, tires, pedals, chain and seat which will likely need replacing upgrading on basically stock bike you buy of this vintage it should bike great bike. Also it has a really nice frame as mentioned with nice color and medium size that should allow a fairly large range of rider size and build options if you want to make changes down the road.

Do you want 26 Inch Wheels?

I'm expecting the OP's next post will be their pictures as found, right?

the double / triple bonus is the bike still has the original rigid fork

can't get a good look at the shifters - if they are original the lubricant/grease inside the shift mechanisms could have hardened to the point where the function is impaired - this can often be solved with WD40 / Tri-Flow

Kool Stop pads will restore the braking power

I'm expecting a "sold while waiting for valuation responses" post.

Yep..I hope not, but that's the most common outcome of a post like this. Good deals can usually be timed with an egg-timer.

It hasn't sold yet. in my searches I saw the ad is still up as of this morning.

I have found clueless sellers like this one often don't bother to close the add for days sometimes weeks after the bike is sold.

Ditto, somewhere between 25% and 50% of the older ads I see have actually been sold. Sellers just don't pull down ads. Frustrating!!