Opg is obtainable? If they are offering a A tier unobtainable for a obtainable, then they are going to scam because overpays are most likely scams. If opg is unobtainable, make sure he is next to you so you can send and if he disappears, get a bad stand so he wont scam your good stand.
Wisteria. They have added a system where the trade cancels when you switch stands and theres also a trade history thing that Odd checks to make sure that people actually got scammed.