Quantum models offers a simple test stand for $20

http://www2.mailordercentral.com/quantummodels/

Look under engine acc's.

For myself, I just cut a "U" in a piece of 1/2" plywood, bolted down a TT .91 4c and mounted the fuel tank behind on a piece of soft foam held down with rubber bands. A "z" bend in an old control rod worked the throttle. Clamped it to a bench with a C-clamp. Cost? Scrap wood.