I dont have so many SPG points but I have very high balances in other programs and when I am on the border like I think this stay is what usually pushes me over is how many nights total is involved and whether I need the stay credit etc. Personally I would be looking at paying for the stay if it was just a couple of nights as I like to see $.03+ for my spg points. Of course everybody is different as you have a lot of points and if you didnt want to spare the cash you might toss your normal guidelines right out the window.