I built a bumpsteer gauge out of a Longacre wheel plate, dial indicator and JUNK laying around the garage. This made for a cheap and easy tool that I have maybe $125 into and less than 3hrs of work. Purchasing the complete kit is around/over $400.
There are even simpler ways to build it if you have access to a bender and want to make it much nicer. My goal was to use scrap steel and not use up my roll cage material or buy smaller tubing and have it bent. If you start from scratch I'd recommend some 1" square tubing as a basic and easy to build frame. Could use small rod ends for the pivots for smoother operation but my junk build works pretty well. The basic U shape base and upright stay the same but I suggest building to the dimensions that work for the jack and height at which you'll be working on the car.
