Im at a cross roads for amps and I need another opinion.

Both are on sale on my local Craigslist witht he Randall RG100G3 for $250 and the Peavey 5150 Combo for $475.

I like to play noisey shoegaze My Bloody Valentine and Whirr, but also like the metal tones of Mastodon and early Trivium. While also getting some really nice cleans.

Which would be better for this sound or just overall? Is the near double in price for the Peavey worth it?
So I had a Randall RG100SC (Gen 1) 212 and a Peavey 5150 212.

The Peavey blew away the Randall but cleans are not its strong point. The 5150 cleans got a ton better with a 12DW7 tube in V2 (or what's V2 in most amps) and a 5751 in the Phase Inverter. Add some Chorus or Reverb and roll off the volume of those high gain pickups and it was pretty decent.

And don't forget about the Crunch button. That's a killer "channel" but it's not footswitchable from the clean channel.

I also eventually put some V30s in the 5150 too.
Ibanez RG1570 Prestige
Jackson Kelly KE3 - MIJ (Distortion/Jazz)
Jackson DKMGT Dinky (EMG 81/85)
ESP E-II Eclipse Custom (JB/'59)
ESP LTD EC-1001FR (EMG 81/60)
Fender MIM Strat

Mesa/Boogie Dual Rectifier Roadster 212
Laney IronHeart IRT-Studio
Peavey Vypyr 30
Peavey ReValver Amp Sims
TOOOO many T.C. Electronic Pedals. . .
Most of my gear is either Peavey or Randall. If it's between those two choices, 5150 hands down (as long as your ok with out a true clean channel).