The TMO stores sell the prepaid sims for about $54.

On eBay, I've bought a handful of prepaid sims for between $5-10 delivered and with $15-30 credit already on them. I've had perfect luck getting local numbers both applied and even ported to these purchased sims.

BTW, my current deal with TMO prepaid gives me 5.4¢ per minute (one year expiration) thanks to a purchase of some discounted refill vouchers on ebay.

Although I'm big on TMO prepaid, I also recognise that TMO's network has HUGE voids in it with no service at all and no roaming there, either. But for most major metro area and most interstates, it's OK.