rebuild or used??

[RPMvulocity]

im in a dilema, so i thought i ask you guys out. should i rebuild my tranny or buy a used one. i was thinking that if i rebuild, i know for sure that my tranny will last for awhile but if i was to purchase a used tranny the question is always going to be there "when is it going to start grinding". if i decide to rebuild my tranny, where around the cities or state can i bring it to get it rebuild. im a poor college student so i want somewhere cheap but someone or somewhere that is some wat familiar to dsm's. let me know guys--thanks