As far as mobile data networks go i'd say sprint is still the best, most of their cheaper phones don't have the dun option though. I believe the centro is the cheapest that can do BT dun without the need for the PAM plan, but that does require a $30 program. as far as simple phones that can do bt dun it's a pretty limited market as that is usually a feature most carriers only allow on smartphones

- as for verizon they have a wider variety of phones that will do BT dun but that generally requires a rather pricey plan or a hack