The current viable options on T-Mobile in the US is the very limited 635 at $120 or a 2 year old 1020 at $540. Something in the middle would be nice. Hurry up with the 735 or 830!
A used Nokia Lumia 925 is an excellent buy. Just bought one last night for $170 in absolute mint condition with everything box, manual etc. And the phone is already SIM unlocked by T-Mobile...
Also since this is your first post here, welcome to Windows Central!
I agree with worldspy99. The 925 is an excellent phone, too bad the T-Mobile variant hasn't received the Cyan update yet due to T-Mobile's slow a$$ attitude on supporting Windows Phone. One can also flash the Latin America firmware on T-Mobile's 925 to get Cyan, off course, Wi-Fi calling won't work.