I don't see a problem with buying used gear provided it's gear that's not significant to a person's life, like used climbing ropes, rope snaps and carabiners, etc. Rope snaps and ropes can have issues that may not be apparent to the human eye(hairline fractures/inner fiber deterioration) and unless you know the specific history of the gear, the little savings you may think you enjoy may not be worth it for these particular items. Like anything though, you're never 100% sure of what you're getting used. You'll just have to do your due diligence and ask a lot of questions along with examining or requesting pictures. I've purchased at least 500 items online and have about a 98 1/2% satisfaction rate and that's due to studying prices, asking many questions and closely scrutinizing the pictures diligently... and requesting additional pictures if need be. (Yes, I mentioned these twice!)
Good luck to you,
StihlRockin'
