I rented a sat phone from Mobal.  They had great service, and sent two batteries.  So I charged em both and took the extra along in a zip lock. (Never used it in 6 days)  I think they charged $9 per day and $2.00 min in 2009. 
In 2011 I rented one from Harlan at Red Lake Outfitters. $16 per day and $4 per minute.  Thing is, when renting from Mobal you need to order it to arrive at your place before you leave and then drive home and mail it back.  So you end up renting the phone at least two days extra or more for me ussually.  So it was six of one and half dozen to pay Harlan a little more ane rent his.  And would rather support his business anyway.  His phone worked great.  I used it 7 days, I always call home at 6 pm.  Talk 5 minutes, and she gives me a weather update.  In 2012 thinking SPOT.
SunCatcher