I've redeemed gift cards dozens of times at Marriott and the regular hotel earnings have always posted.

I also think that on at least some of these, the GC purchase itself has posted to my CC as a Marriott purchase, earning 5 points/$. So in essence, I get the full 20 points per dollar as a Plat member.

But I can't swear to the 5 per dollar for buying the card.

In my math, I calculated that I'll give up 4 points per dollar (worst case). I didn't do any discounted cashflow analysis...I'll empty the card almost immediately and I burn through RR2.0 credit lightning fast as well.

So it's somewhere in the $80 range. Or maybe $70, or maybe $90. For about 30 seconds of my time. I'm even having the card sent directly to the appropriate Marriott so I can get the package from the front desk, open it, and have them post it to my account right there.