How does boost mobile phone service work?

i had a cricket phone and my whole screen fell off and im kind of tired of cricket wireless so i was thinking about going to boost mobile .. i was looking at the sanyo incongnito which 79.99 and then the service which is 50 , does boost mobile do the first month free or do i pay for the service too which should be around 129.00 i think ! and do u pay an activation fee ?How does boost mobile phone service work?you pay for the phone and monthly plan up front. No activation fee. Plus boost now has $50 w/shrinkage, which means that if you stay with them for 6 months your monthly plan drops to $45, 6 months after that down to $40. It can drop down as low as $35.