More realistically, the Apple reseller I bought the iPad Mini 2 from is selling that model for $395, so they may well buy it in for around $300.
The original purchase was partly-funded by trading in my Cellular 32 GB iPad 3 and WiFi 16 GB iPad Mini. Between them, they accounted for $570 of the $749 purchase price.
They offer a trade-in on used items: send them the details & make an appointment for them to check the device, mine's always been in a case, so is immaculate. If their offer is acceptable, you get either a store credit or a direct deposit to your bank account.