Well, my truing stand costs 0 $.
I simply install and true my wheels on the bike, using the fork blades or the stays as guides and a little screwdriver as feeler. A truing stand would be quicker, but I don't think it would be much more precise.
So if I were doing wheels for a living I would definitely get a truing stand, but since it's a hobby and since I usually don't have to redo the wheels I have done, my need for a truing stand is very limited.