Two of my kids have Straight talk unlimited plan for 50.00 a month and they love it. My daughter paid more for a "better" phone, as she puts it, and my sons cheaper phone is holding up better! She is really rough on phones-so get the base phone and try it out first! My son says he gets a reminder on his phone to renew his service so we get a new card for him at WM the week before it expires, then when he gets the reminder he just renews that day.
Good luck!