SIM unlock the TP2? Low cost plans available?

[onree]

So I recently had to switch over to an Android phone, thus stranding my still-ticking Sprint TP2. Does the SIM Unlock process (the one that you have to pay $15 for) still work? Is it worth trying it to get an unlocked TP2? I would do this to then give it to my mom.

Which leads me to my second question -- does anyone know of any low cost plans (I'm thinking prepaid, for example). Some minimal data included would be great.