if you're just needing to true and not build, zip ties or index fingers on the seat stays is about as affordable as you get. worked fine for me for 20+ years, then i got a used park because what respectable home mechanic doesn't have a truing stand, right?
...and i never use it because it takes longer to remove my wheels and mount them in the stand than it does to rest my finger on the stay and move it until the rim scrapes my fingertip and give a few turns on the nips.
size pretty much summed it up like a champ. ive owned two ts2's (at separate times) and ended up selling both. thinking back at it, it was a dumb ass idea, but i needed money.. i honestly dont know what other truing stands are out there cause the park one is so awesome, although i am sure there are other neat ones out there too.
since then, i just use zipties and my finger like size.. not as easy and you have to pay attention and not be distracted with anything else. it also seems like it takes me a little longer, but it always works in the end and is free (aside from the zipties and your time).
'poor people problems'
if you do get the park one, you have to get the tilting base. its useless without it, unless you plan to mount it to something.