Price is important, I'm a full time grad student, no job, zero income. I have a prepaid t-mobile cell phone account. I lost my "dumb" flip phone. It was OK and I even liked it because it was very small and fits in a pocket along with car keys and what not. I pay by the minute and typically us about $15 worth of minutes each month. So I do NOT want a $50/month cellphone bill. Can I buy a older model used iPhone and connect it to my existing t-mobile account? I seriously do not need any phone features other then voice and text. I almost always have my Macbook and WiFi. What is the lowest price option for me?