Alright, to clear up confusion with the ordering system I have explained it very specifically below. Hope you're all not still scratching your heads....:)
If you buy 1 copy of a core mini, like a MadCat, you get 15% off.
If you buy 2 copies of a core mini, you get the 20% off price.
If you buy 3 copies of a core mini, you get 2 @ 20% off and 1 @15% off.
If you buy any less than six copies of a non-core mini, like a Spector, you get 15% off.
If you buy 6, you get 20% off.
If you buy 7, you get 6 @ 20% off and 1 at 15% off.
If you buy all minis in sets of 2 for core and 6 for non-core, you get 25% off the total order!
Hope that clears is all up!