Room rates in Las Vegas can be very low during summer but November until February often hover around $200 before the mandatory resort fee. I booked the SLS Las Vegas (Review) for $40 last year during summer (but I later regretted that decision).
Availability using the GO FREE 15,000 awards rate is usually pretty good even at the weekends. The good news is that you will not have to pay a resort fee when using points.
However the 3,000 points GO FAST will give you just a minimal discount – but likely also waive the resort fee.
If you have a winter stay coming up over the weekends this is a great option to consider.