Straight Talk 45x12= $540/annually
My setup:
Consumer Cellular flip phone (500 Min) 21x12= 252
Verizon Hotspot $90/mo x 3 months in the Rv 270
Total cost 522
So for me, it is still slightly less expensive to stick with 2 different plans. I love my Consumer Cellular service (ATT network) and Verizon's 4G. I'm using Verizon's prepaid service which is very flexible and can be purchased for 7 days, 15 days, or 30 days.
And as far as the whole smart phone thing, I'm perfectly happy with my dumb phone. I use my laptop when I need to access the internet.