Found one used for $120. 100 watt iI think. Good tone?

From experience, really bad. Really synthetic tone, the lows sound like crap. I would look into something else.

Could you add some more info? Combo? Head? Model?

Probably not very good.

not worth the 120. I've never liked any solid state Marshall head i've heard.

If it's something like a MG half stack i would stay away from it.The head itsealf isn't bad (but it's not that good either.It's a little low in the gain department.) but the speakers Marshall had custom voiced for those amps sound like shit.You can get good death metal sound out of it if you put different speakers in the cabnet and run your guitar signal through a overdrive and mixer BEFORE the amp input.

Save some more cash and get a Valvestate instead.

Basically compared to the solid-states or valve-amps of some other companies (Peavey, Vox, etc.) Marshall isn't really that good (flat sound, it misses the depth). I'd suggest you'd buy a vox valvetronix or a peavey vypyr instead.

The old Valvestate amps are great for metal. Chuck Schuldiner used them exclusively, and Jarno Anttila uses them.

The MG amps are maybe not quite as good as the Valvestate amps, but you're just not going to find a 100 watt Laney or even Peavey head for $120.

In my experience, a good player can sound good with cheap gear, and a bad player won't sound good with even the best gear.

(edit) Use your ear, trust your instincts.

I came here to mention the Valvestates as well. Great amps, you can find lots of vids for them on YT.

When it comes to solid-state, stay above 100 W and away from the MG series.

This, specially. And if you're going to play live (which I guess is what you'd want a 100W amp), you want to avoid shitty basses.

Best you can do is save some more and get something better, for that price I doubt you'll find anything above 100W of even remotely decent quality.
But, if you really need to buy it now or can't raise the budget at all, I suggest you do as Einherjar said and check out another brand, maybe you'll find something better.

Oh by the way, some of the combos have an open back cab. Not good if you're looking for a tight bass response, which might explain part of the dislike for their sound.

I'll think I'll save up for a Valvestate.
I've inherited a practice amp from a (now ex) girlfriend's dad who no longer played guitar and it doesn't really sound nice. (Crate GX-15).

I use my guitarists' Valvestate for practice/guitar-to-guitar rehearsal, and while it's old as fuck and falling apart, with good EQ-ing I can get a great death metal tone out of it(think Left Hand Path, Scream Bloody Gore). Definitely can't do more than practice or jam(minus drums) with it but the tone is really a lot better than one would expect from a Marshall practice amp.

Ok dont think Im stupid. But ive never used them, but what is it a power amp? I found one, for like 150. Its a marshall valvestate 80 watt, modle 8008. It has a button on the right, and a channel a and channel b knobs. What is a power amp, what do i use it for....and should i get it?

Be careful not to get the Marshall Valvestate VS-series. Those aren't that good for metal.

The one you should try to get is the Valvestate 8100.

The solid state Sunn's are really good though. My Beta Lead is terrific.

Marshall are no good for solid states. If your looking for really good affordable solid state combos, go with peavey.

I have a Marshall Mode Four halfstack that I really enjoy (aside from the clean channel, which is weak), but I personally know two guitar players who have blown the same kind of amp...one at a routine gig, and the other at a routine rehearsal. So I'm a little worried about that.