Do you really have to ask before accepting that deal. If I knew who was offering you that for those jewels I'd try to step in and steal that trade from you myself. What you waiting for ?!?! Make the deal already.
Maybe hoping your inv will be too full to hold it all so he can do a switch?
Or could be duped. Those max jewels don't exactly drop like candy but purty well close enough that the ss alone is insane for 3 of them in my books