What I've learned to save money:
1.) Those racers that seem to have bottomless money pits of parts, tires and tools, usually don't. They just know how to maximize thier budget and not be wasteful. Chances are that the guys you think spend a ton, really aren't. (If you figure how much they spend per race, they may race more often)
2.) Buy quality stuff once. Avoid the fancy new thing, stick to tried and true. Ignore sponsored drivers. They are paid to say good things about products.
3.) Xray, Kyosho, Mugen
4.) The Hitec 7955 servo is the only servo that exists.
5.) Airtronics M11x is extremly reliable and lipo ready (Tx and Rx both run well on 2s lipo Rx packs). Avoid low end radios, especially the old cheaper Spektrums.
6.) Hobbyking has Rx lipo packs for <$10 and good Turnigy chargers. The Turningy chargers are actually better and easier to use than my expensive brand chargers.
7.) Don't buy race tires and practice tires, or hard trires for practice. Oncce your race tires have lost thier edge, use them for practice.
8.) Ofna Truggy box, 4500 4S1P lipo, and an adjustable glow driver. Screw those little battery drivers.
9.) Stick to full race mills, but avoid fancy engines. The OS .21XZB is plenty. Avoid cheap mills.
10.) Buy bearings in bulk.
11.) Ace hardware has plenty of shims, washers, and Hex screws for RC. Grab a ton of setscrews.