UPDATE: Forum member roar15 has shared a doorbuster coupon for $20 off any LEGO purchase $75 or more for Saturday 12/18 from 6 am-1 pm, in-store only. Not sure if this can be combined with the existing 20% off, but if you can get it to work, that would bring 8129 down to about $75! Definitely worth a try. Good luck!
Sale runs Friday 12/17 and Saturday 12/18. You will also get the free 30005 Speeder Bike with purchase.