You should have enough sense not to blow all your money on clothes.
Literal
Clothes [on-に] money [object-を] all use-[regret-しまう] not [amount-くらい-の] discretion [object-を] hold-should.
A complex sentence. ~ないくらいの ('not-to-the-extent-of') frames the level of discretion required. ~べき ('should') expresses moral obligation. 分別 ('discretion / good judgment / common sense') is the object of 持つ. 使ってしまわない is the negative of 使ってしまう ('end up using / squander').