Tracfone Minutes Expiring- Need Advice

Hi, I am asking around at different cellphone sites, trying to find some advice on Tracfone.

I am not really all that familiar with cellphones (I don't even own one myself), but my 78 year old father has a Tracfone with a year's worth of minutes which are going to run out in a few days. He uses his phone only occasionally when he is out and about to let us know he is ok, and of course it is also there for emergencies. He lives in San Diego county, CA and is perfectly happy with the service he gets. Since his minutes are about to expire, I wanted to stop his minutes from expiring by buying him some more, which as I understand will allow his current minutes to "roll over" until the new expiration date and be added to the new ones that I get him.

My problem is he still has more than 250 mintues on his phone, which would almost certainly be enough to last him another year, since he's not a heavy user. My local store has a lot of different Tracfone card options, but they all seem to come with different expiration periods, and I can't figure out a cheap option for me to add a small number of minutes but to also extend his total minutes by at least another year. I don't want to waste the minutes he already has, but they're going to run out if I don't extend them by rolling them over with a new card. $100+ is a large sum of money for me, so do I have to spend that on one of the yearly cards, or is there another (cheaper) option I could take? Maybe it would be cheaper for me to just let the minutes expire and go for a different product, something that would suit my dad- is there another cheap and reliable service out there that would not require a contract that I could give him for less than $100?

Thanks in advance for any help or advice, I really do appreciate it.