Looking for where the cutoff is for keeping the Phaser on, or turning it off.

We have a Xerox Phaser 8550 - and we print to it about once a week. However, we feel like it is burning through a ton of ink being left on (in powersave). We would like to turn it off but are worried about it either clogging up if it is left off, or breaking with the on/off cycles. 

So how long do you need to go between print jobs to before it makes sense to turn on and off the printer between jobs.