Prepaid Plan...

There is only one, the 25 cent per minute plan. You can text with that plan also but you pay per text. You aren’t charged unless you text.

Comes to about $8.33/month if you put $100 on the account (1 year expiration).  As long as more money is added to the account before it expires, the money builds up in case there is a heavy usage month.  Note, smaller payments have shorter expiration lengths.  Not much out there cheaper than this directly with a major carrier, most want you on a monthly plan.