Upgrading a rank during a sale

[pixlii]

I have Noble rank. I'm planning on upgrading to Overlord during the Black Friday Sale in a few weeks. The page for buying a rank says that I "only have to pay the difference". Will this mean I will pay $10 for Overlord ($25 for overlord - $15 for noble) or a different number?

 

[ARMcPro]

the sale is calculated on the full price

so 100-15 then the sale will apply, so it will cost you 21.25$ (or that is how it was last time someone asked Jeremaster)