Board Thread:Suggestions/@comment-26884596-20160828223101

It would go like:

Colt Python (Tier 1) * 2,000 Gold

Colt M1911 (Tier 2) * 5,500 Gold

Glock 37 (Tier 3) * 8,000 Gold

Desert Eagle .44 (Tier 4) * 12,500 Gold

S&W .500 (Tier 5) * 22,000 Gold

I'd say you should get at least 50-500 kills to unlock the next gun in the tree. 