Guys, I don't think you really are thinking this out...
I'm positive there are likely some type of peering arrangements that the mobile providers have that allow for a certain amount of roaming time on each others towers. At some point, there are likely fees associated. If the original poster is using roaming excessively, it's very possible that Sprint is either losing money, or coming close enough to losing money that they don't want to take a chance.
As a business owner in a related field, I can say from experience that there are times when it makes sense to fire customers. It's just not working out. I'm sure he isn't getting the best service possible either and would likely be happy with someone who has native towers.
I'm in Maine right now roaming, and it completely sucks. A good portion of my calls are going right to voicemail etc. I can't imagine having to deal with roaming all the time, no matter how great the phones are with Sprint.
Just my .02!
