My flatmate's dad owns a contracting company. He has 11 cellphones for himself and his employees; which are connected through vodafone. His contract includes talkZoneZero 30 ($30 per phone so that the 11 phones can have unlimited calls to each other), and an 0800 number but most of the $2000 per month bill is spent calling other landlines and cellphones (i.e. clients).
Anyway, my question is this. Would it be feasible to save money by buying smartphones and using voIP software for this? Here are the requirements/preferences:
-11 phones, preferably not too expensive
-able to call each other a virtually unlimited amount
-cheap calling to others, including other mobile numbers (currently paying $0.30 p/m for landlines and all mobiles apart from the 11 in the talkZone
-must be reliable, work in rural areas (XT as provider perhaps?)
-must have non-terrible call quality
-must be relatively easy to use
-would be very good to be able to keep the same numbers, not utterly necessary though
-possibly keep the 0800 number?
Any advice most appreciated!