Normally $499 and difficult to find stocked let alone on special!
Credit wholly due to the respective posters and commenter durd0008
Just highlighting the bargain for others as I have an IFTTT alert set up for Lego Mindstorms which did not trigger due to "Mindstorms" not being in the title.
20% off at Target - Yiey
10% off with eBay deal - xkp
$499 * 0.8 * 0.9 = $359.28
(499 - 359.28) / 499 = 28% discount
Terrific price
Wish I had a kid to use as an excuse for buying this set; I imagine it's a lot of fun.