i've bought used tires before plenty of times. and ya know what, sometimes in a pinch when you've got 19" wheels and a tire is punctured and not repairable you really have no other choice but to scrounge around for whatever you can find (and "nobody" stocks new 19" tires, especially not the size we're "supposed" to have on these journeys)
i stepped up my tire size to 255/50 19, with this used set - i'm glad i did because for $100 for a set of 4 i can decide if i like how they feel, if the clearance is enough, and if i'm going to get this size again. $100 is a much nicer price for an experiment than $1,000.
ps: i've now put 20,000 miles on these experimental used tires, which is more than i got out of the first set of kumho's that the thing came stock with.