Walmart.com is now including a free month of unlimited service (a $45 value) when you purchase the Straight Talk Samsung Galaxy Precedent at the regular price of $149.98. Free shipping is also included.
Seeing as you would have to pay the $45 anyway before you could actually use the phone this deal makes its effective price $104.98. That's the lowest price yet for the Prevail which is a solid entry level Android device which most users seem happy with provided they have coverage their area.
The Prevail runs on the Sprint native network (the same as Boost and Virgin) which has a smaller coverage footprint than AT&T or Verizon which other Straight Talk phones use.
See Coverage Maps For All Prepaid Carriers to check if the the Prevail would work for you.