I started this morning by logging in with the URL for the $50 off $250 (very important to remember the URL for later).
I ordered a Brother HL-1440 laser printer for $299.98, less $50 instant discount and with a $50 MIR gift card back to Office Max. I added some pens to get the discounted price over $250 so I could apply the $50 off $250. When I got to checkout, all was there as expected, but no $50 off $250.
I called the 800 number and explained what I was seeing. The helper told me to go to the next screen (complete the transaction) and the $50 off would be on the screen. It wasn't, but now I had ordered the printer. After lots more talking, including going back to the printer item page, they asked for the URL I had started with and then credited the $50 directly to my credit card, independent of the purchase.
With careful add-on and counting the rebate, this current deal takes the price down to about $150 (plus tax). If you can hit the $50 off $250 from Ebates, it would be even better.
Gee, I suppose if I now cancelled the order...Ah, never mind, I really want the printer. They say I'll have it tomorrow, free shipping.