Will motorola i930 or i850 work with tmobile deal? and how much does these phones cost?

Question

currently i have tmobile deal and razr phone if i switch will it work fine?

Answer 1

If the phone is a GSM phone that takes a SIM card, it should work. T-Mobile and AT&T both use GSM, so their phones are generally interchangeable.

Answer 2

No.  Neither of those phones will work with T-Mobile.  T-Mobile's phones and network are GSM.  Nextel's phones and network are iDEN.  While both use sim cards, they are still two different technologies and are not compatible with each other, even if unlocked.