You can afford the Devastator even on DOMINATING with no trouble, though you do have to plan for it a bit if you've also tricked out your house and bought some Super Steel. On Hard and lower difficulties, you can accidentally end up with enough money to buy everything.
Get an effective Tailoring and/or Mechanics score of 50 and you can make improved repair kits, which will mean you can turn your trash tier equipment into large profits. With Expedition, every build can spare enough points to get at least 50 effective in both.
If you're a crafting-heavy build, the Disassemble feat will pretty much solve all your money problems, if used well.