Mine is 7+. I'd love a phone for free but then I lose my unlimited calling and data as I would have to switch to a more expensive plan. Buying a phone outrigh

Mine is 7+. I'd love a phone for free but then I lose my unlimited calling and data as I would have to switch to a more expensive plan. Buying a phone outright costs more than a computer. $1200 for the latest samsung. A two or three year old phone could cost $500.00. I do need a new phone as the buttons barely are able turn on the screen but I see no viable upgrade path.