First of all we don't know what the earning potential of Chocobo Racing at higher tiers are like. 1st place in R80 nets you 117 MGP which takes me an average of 2.5mins (+loading). How will R500 scale? No one knows.

Not EVERYONE is gunning for that Fenrir mount, I have little interest in it myself. But because MGP is worth nothing outside of the Gold Saucer, the place needs these costly rewards so players will take time to acquire it. If you could earn 1mil MGP in 1 week, possibly get all items in 2weeks, why would you ever set foot back into Gold Saucer after that? Gold Saucer would really be a ghost town after a single month then with only NPCs to entertain you. No one buying Cactpots, no one doing GATE events, you'll be racing your Chocobo with silent NPCs. Is that how you guys want it?