I have a pay as you go that I add to on 60 day $25. Being a senior I do not use the phone that often therefore I accumulate minutes that I may never use but update every 60 days for fear of losing accumulated time and value.
$100/yr is good but it`s going up 66.5 % in cost on july 20th 2015!!!! The cost was 0.30/min and it`s going to 0.50/min(almost double)
Unfortunately all phone companies require you to top up to keep your funds and service however you might like to consider the 365 day option for $100 which works out cheaper than $25 for 60 days.