American Express periodically gives you discounts on Amazon for using Membership Rewards points and now they’ve expanded the ongoing Christmas offer, so check here to see if you’re eligible even if you weren’t before.
Discover jumped on the bandwagon too with more people targeted for a rebate for using at least $0.01 in your cash back balance. Check here to see if you’re eligible. This one was only $10 back for me, so I’ll still do it, but I’ll be frustrated the whole time that it’s only $10.
My recommendation? Buy a $125 BestBuy gift card and resell it at 98% of face, and get $50 off during your purchase by using one Membership Reward point. (Or if you got a lower offer than $50, do what’s right for you.) Scale down as appropriate for Discover.