Tools? Nothing great beyond stacking a 20% off with a super coupon at Harbor Freight. Always figure out which cashiers don't care and stand in their lines. It's usually the long one.
Those coupons have been a source of great amusement. I'll print off a sheet and hand them out while in line. (strength in numbers when it comes to an oddball coupon) One guy refused to take one, said they wouldn't take it, gave me a lecture about photocopies, then 2 minutes later was tapping my shoulder, "uh, sir, could I get one of those?" after mine was accepted. Another time I hand one to a couple of guys kind of bickering about money. They instantly shut up, one says to the other, "go get that saw."
Probably the best deal on the most worthless thing was $15 for a big box full of crap from Radio Shack. We get it home and it was full of token ring connectors and stud finders. You cannot build a balloon frame structure in the USVI, everything is rebar and cinder block. Words fail me when I attempt to describe the sheer uselessness of a stud finder in that part of the world. We threw away at least a dozen of them in the package.