cpa ? and answer . can i get some feedback on this question. thanks

I found this question on another forum that's several years old.I am not interested in ppv just media buys, so MY question is sitescout still a good place to start with self serve media buys? I see that pof is recommended as well, also can someone explain the answer why does it cost more to test a higher paying offer , if im placing direct links on a website and buying cpm ? HERE IS THE ORIGINAL POST : (question) :I am going to move from PPV to media buys (or at least add media buys). It seems the volume in media buys is several times that of PPV . Should I begin with sitescout? It seems like the easiest to get started in. Are there any resources you would recommend before I get started? I under I am probably going to lose a few bucks while I learn, but just want to learn all I can.
(answer):It also depends on what vertical(s) you are most comfortable with and what offer you are looking to promote. It of course takes more money to test a higher paying offer.

CTR is of course going to be key, so don't stop testing!