Straight Talk Android Phones to Run on Sprint's Network

I was thinking when I seen Straight Talk offer the Galaxy Precedent that this would be the best deal in the cell market. I mean a CDMA Android phone with a decent processor and screen size on Verizon's network with unlimited everything for $45! What a deal! WRONG. Then I read that Sprint just signed a deal with Straight Talk and the Samsung Android would use their network. Bummer as Sprint's native network is so much worse than Verizon's. My next thought is, WHY would anyone do this with ST? They charge $45 and Boost if you are with them for 18 months lowers there charge to just $35. Plus you can get Boost cards at a discount to face value where that is very difficult to do with ST. Same exact phone, same network, same calling plan but save $10-$13 more per month? Why not go with Boost?