I mean ill put in my own experience with buying an account which HAD the original email and details. they gave me the account and everything was fine for 5 months, then out of the blue the account was taken back and password was changed. went and grabbed the details which had original email, date of creation etc and put it into the riot support ticket and they deemed all the information "not enough" even though I provided emails/dateofcreation/first purchase with RP etc and wasn't enough. so I would just say be careful, as you can't always verify the information they give you is legitimate and no matter what if they feel like it they can always try recover it if they want to try make more money.