The last 20 rentals and the weighted average were screwing up pricing and were inaccurate due to the mixture of demo rigs and long term leases.
Your pricing should be based on your off lease pool payout + your profit margin. Not on anyone else's prices or profits.
Normally charging the last rate on poolpicker.eu gives you a 10-20% profit margin and will get you leased most of the time.
I can look up or test your pools Btc per mh per day if you'd like.
I pay attention to Poolpicker and do pretty much what you suggest here. It's just also helpful to see the rental history and factor that in as well (while trying to recognize special cases like you mention). I can live without it I suppose.