Much to my surprise as I was on MyVegas I noticed for the first time Bellagio offering a $100 Free Play reward! I am assuming this is a new addition, as it is not something I saw before. I returned the $50 FP I has recently purchased to have enough coins to get the $100. It's funny though how the "math" works on these rewards. $50 FP is 150,000 gold coins, but the $100 cost 400,000 gold cons. But they got you as you can not buy two of the same reward!
They had added $100 Freeplays about a month and a half ago, but they were for a limited time only and expired at the end of June. Only certain people could see them (i.e. only people who had purchased a lot of chip packages were allowed to buy them).
The "math" is simple; the larger rewards are theoretical more valuable. Therefore they are not double the "price" of the lower rewards, but more.
I don't see the $100 free play option. Are you currently limited to 3 MGM redemptions are have you purchased chips in the past and are elgible for 4 or more redemptions?