The Cost of Running

I just got the new issue of Runner's World in the mail because I ran a lot in the last year.  Don't be jealous.  After not actually reading it at all, my wife did and noticed something really strange and weird.  These are the three subscription notices in the magazine:

They are similar to the ones in every other magazine except for one thing - they are all different prices!!  It is a little tough to see but each ad has a special for 24 issues at a different price.  One is $14, one is $20, and one is $24.  Why would they do that?  I feel like they are tricking me somehow but I don't know their end game?  TELL ME WHAT YOU WANT, RUNNERS WORLD!!!!!