Slowpoke aside, knowing how good Jz is as a coder as well as a nigh perfectionist, 350$ is cheap af for the coding alone and you just simply don't understand how tiring it is to get things work just like source.
Also , the only reason this offer is not taken because it is fake as Jz did not make this offer (his account was hacked and the hacker posted this offer to scam other people).