I don't know much about cellphone plans,,  but i do know that  300 Mins  wont last you a month carl,,,  unless you do most of your talking at night  (after 8)        it's good to have for  $29.99  and the Nokia 3390 is a very nice phone (mom has one)  but i would go with  the   600 mins,, or even more ,, it's worth it, cause if ya go over , you wont be happy at the end of the month
If you are afraid of going over your anytime mins limit,, do what i do,,  get a 'pre-paid'  account,  the phone IS NOT free this way, but  it's alot cheaper in the long run  (you can buy  $10 all the way to  $100  minute cards ,, and they last you a month and cost less,,,  and there is no   $300. Bill if you go over,, cause ya have a limit,, and if ya run out ,,, just go to a local place that sells 'em and put it in,,, VERY EASY done ,, even i can do it  
 
   
just my opinon ,, and if your looking for a good pre-paid    Provider,,, AT&T is one of the best , T-moble (VoiceStream) is right up there as well  

        Make sure you buy a case to put the phone in!!
,, salt air and atmospere is not good for them phones,, ask StarsnStripers, a  LONG day on the water disabled the keypad  
 
         
good luck!