Comments of chapter undefined of I Became a Pawn Shop Owner

I’m confused in this chapter; the system told him he could charge up to 10% for profit, but then nothing bad happened when he charged more than that. Original price: 20 spirit stones 10% would be 2 spirit stones Maximum price with his profit should be 22 spirit stones. But he charged 25 spirit stones; this gives 25% profit (5 profit / 20 original price * 100%).

wow... I was expecting a beautiful stuck up beauty with an important lineage to enter.

Okay start however the grammer needs a lot of work.

I thought there will be some price negotiation, but there was none.

its remind me of "not a demon god lackey"

Thanks for the chap