Honestly, the sale I go to starts at 5, and they sale tack and stuff, all the horses are in the barn and out side, and you can test ride them and pet them and get to know their personalities, you can buy them outside the ring, usually for a high price , but then you know you are getting them, or you can wait and see what they go for in the ring, but with that other people will be bidding and you may not win if the price goes out of your price range, but usually it's cheaper in the ring. Sometimes people do drug the horses, but there are alot of good people there as well and if you ask the right people or take someone really horse savvy with you they can point you in the right direction on who drugs, and which horses are drugged or not.
Frankly last friday when I went there was a lttle buckin mare there, and I swear she was drugged, because of how she was carrying herself. BUT it was because her rider was WAY to big for the little gal, causing her to look drunk and dizzy. But there are tons of kid safe horses, again last friday there was a 17 h TB with a little 2-6 year old riding it around all over the place, the poor girl's legs didn't even reach half way down the gelding's sides lol, just bring someone with you and do not rush into a buy, there are plenty of horses and if the ones there arn't perfect then don't bid, just keep waiting and watching and one will eventually come along.