That's just madness ($(C)20,000 for 12 copies)) = more than $(C)1,500.00 per piece.
They've never been that hard to find sealed on Amazon for ~ $100 - $150 (same item still sealed).
I see that this auction is still listed.
If you send the entire case to VGA, you can get these graded as "uncirculated", which will inevitably be more desirable for collectors. If the boxes aren't banged around inside, each of these games should get a gold rating (85+ or higher), which is also the goal for most VGA collectors.
$1500 definitely seems too high for a reseller. There is no room for profit. You can currently buy a VGA 85 copy for less than $500. The seller of this sealed case would need to add the "best offer" button to get any nibbles. The price would currently have to be around $6000 to see a reasonable profit.