Based on this review it appears the Ting Mobile phone service can start for as low as $36 approximately, including a new flip phone, 500 minutes that don't expire, i.e. rollover minutes, and 100 text messages. There is a basic $6 month per line fee and the mobile phone coverage map is on the Sprint network, so all appears good. Details are here: Live Action News review of the Ting Cell Phone Plans.
Go here to activate a plan and to get the $50 off coupon for the Ting Cell Phone Service.