At time of writing I can load a cart with the MOQ of 3x lots of 20x 821s and start the checkout process.  Now maybe that's as far as I would get, but assuming they validated the order then it appears that one buyer could purchase 60x 821s (66 to be exact since each lot includes 2x "free" units) for $120,825, including shipping.  That works out to about $1830/miner.  Not exactly a steal, but better than the prices from Canaan's approved resellers.