It's a possibility that it's to do with the prices that RFC have no control over.
The AFL froze GA prices last year so it wouldn't surprise me if there is a decent rise in prices thanks to the freeze last year, as well as someone needing to fund the new stadium agreements that like it or not, will be expected to be put in some part on those attending the ground.
I doubt it's purely a price grab to see them rise by so much.