Run Garry's Mod 13 with no Source Game?

My friend only has $10 and want’s garrysmod. Will he be able to play things like spacebuild and trouble in terrorist town without a Source game WITH garrysmod?

From what little experience I have with Garry’s mod I think you could. But his textures may be wonky and it may take him/her forever to download the content for the server.

Somebody correct me if I’m wrong.

He could “play” TTT without CSS but it would be awful since most of the content used in the gamemode is from CSS.

He could get content addon, so he doesnt see any checkered materials.