Rather than lowering the fees:
1. Buy a month, get a month free.
2. Buy six months, get eight months.
3. Buy a year, get 15 months (and-or a tee-shirt)
4. Sign up a new premium member and get a month free.
5. Sign up a new premium annual member get three months free and-or a tee-shirt.
Giving freebies is always less expensive than cutting prices.
Edit: you could always sign up at RB with a mmmaryXX (where XX is a number), invade otherwise peaceful threads, and then offer them sanctuary (under a different alias, of course) at IHub -- or just skip all of that and threaten them with her if they don't migrate. Almost anyone would spend $10+ a month just to get away from her.