Used I am looking to spend around $50. Double x 8 Speed or x 7 speed would work. Let me know if you have anything email@example.com
Given that cog spacing is .2mm different between shimano 7 and 8, get the correct ones. Also be advised the RSX 7 speed front will shift a double or triple. If you want a triple front in 8 speed,they were specific and only available in RSX,RX-100 or 105 models.