Cost of massplanner modules?

I'm only trying to use MP for IG so i'm leaning towards the 10$ edition and just getting the single IG module that they offer (Scheduled posting) but I dont know the price of these and I want to first make sure if it's worth over the full 20$ edition... Does anyone that uses MP know the price?

Also what is the deal with the "Instagram poster edition" for 17$? Seems kind of expensive considering it's only for ig...

Thanks is advance

Anyone?
So many MP users but none want to help out :s