WGT must have stats on what fills up quickly and what doesn't. Any reason why they can't have the same course RG and have 2 different entry fees? 50c and 1k? for the popular ones?
If everyone loves certain RGs why not set loads of them with diff prize money/entry. Throw in a few not so popular every now and again to keep the bored people happy, again one with low $ entry and another with high $ entry.
Just needs a bit of a strategy me thinks. Making it public would also help as you could get better feedback from the players.
I'm losing money in RGs so don't matter to me what happens ;)