Russian discount for engineer gates?

Hey people!

Has anyone else noticed the Russian discount in the Ermelinda's bundles?

Here's what I mean. The prices are in my local currency – the Serbian dinar, which shouldn't matter in this apples to apples multiplication comparison:

Taster Ermelinda bundle: 
-6x decals
-5x starter
-Priced at 508.90 RSD

Small Ermelinda's bundle:
-12x decals (twice as many as taster)
-10x starter (twice as many as taster)
-1x Blitztrager key (actual bonus)
-Priced at 1,017.80 RSD (exactly double the price of the taster)
-Yet it says 5% off. Okay. Maybe it's the key that's discounted.

Medium Ermelinda's bundle:

-24x decals (twice as many as small, 4x as many as taster)
-20x starter (twice as many as small, 4x as many as taster)
-2x blitztrager key (twice as many as small)
-Priced at 2,035.60 RSD (exactly double the small price, quadruple the taster)

-Yet it says 10% off. What exactly is 10% off? Cuz it sure as heck isn't the price.

Large Ermelinda's bundle:

-60x decals (2.5x as many as the medium, 5x as many as small, 10x as many as taster)
-50x starter (2.5x medium, 5x small, 10x taster)

-5x blitztrager key (2.5x medium, 5x small)
-Priced at 5089 RSD which is exactly ten times the taster bundle.

"15% off". Off of what exactly? An artificially inflated price, where we could invest the difference into 10-20 more gates?