A higher price for the tokens probably would not translate into a proportional increase in earnings. If prices go 10x, earnings might only go 3x. A 10x price increase implies both many more new accounts and a vastly increased incentive for existing users to be competing for the reward pool. Also, people who now give out 10 100% upvotes a day might well shift to 25 40% upvotes per day.

Granted, curation earnings would go up proportionally for whatever staked HP a user had, but the same cannot be assumed for author earnings.