Thanks for the help!

After looking at all the info, I think what I read before was someone suggesting to buy the 165 plat for $19.99, then you can spend 75 plat on opening campaigns (if you do bundles when possible) and have the rest left for spending on other stuff.

Now I just have to decide if I want to just buy 75 plat for $9.99 and just open all areas or go for the $19.99 for 165 and have some left for shopping