What to do with 42k gp?

M12s
42,000 GP

Lulz. GP crates aren't worth their salt.

Winchestor or Anaconda if you can 1 shot.

XM8 or G36k if you like wall-shotting.

Some of these ^ guns need more GP though, I recommend spending some of your life in Mutation mode till you save up for something you like.

If you want a fun gun with your usp, go for uzi or winchester scope. Or you can always wait for the halloween patch?

definately winchester scope.
Make your friends buy it too and play winchester only, most fun ever.

Nothing, just save it for the next patch.

I would recommend getting all 4 bags for as long as you can with that GP. It's really useful if you want to use other guns while in game, but you can really only choose between one sniper and one rifle some of the times. Buying the bags would probably make your bags look like this:

Bag 1:

M4 / M4 C with a Deagle / Deagle C

Bag 2:
AWM with a Deagle / Deagle C

Bag 3:
AK Silver with a USP

Bag 4:
Aug / K2 with no pistols.