Here, let me pay you $700 for this item that’s worth $500 and you can just send me the extra $200 difference. I have to do it this way because it’s your father’s, brother’s, nephew’s, cousin’s, former roommate’s will and I’m just signing the whole check off to you.
Meanwhile the original check is fake and now you’ve lost the original item AND $200 and the bank is investigating you, and not them.