iStore discounts

Currently in the iStore, you are able to purchase items in stacks of 64 or multiples for a small discount (15% is what it looks like). However, the discount is applying twice. It is recreated fairly easily:

Go to the iStore and purchase 64 blocks of Ice (100 KP apiece)
Check the total for all 64 in the checkout: It lists at 6000, not 6400 - Simple math shows this is wrong.
Below the total, it says an additional discount of 400, and you will be paying 5600 - This is the discount being reapplied. Truly, the total should be 6000, not 5600. This is showing the discount applying twice.

Maybe this is how it was supposed to be done, but if you also go back to the same example and do the following:

Buy 63 ice blocks
The checkout total lists at 6300 with no further discounts. This shows the initial purchase having a 400 KP discount invisibly in the first example.

When purchasing in the past, I noticed the lower line in the first example (That is, the 5600) was what I was charged, not 6000 - Which would be the correct discount.

I think looking into this would benefit the admins to actually make sure the right prices are there