I didn't get why it is here. Could I rewrite the sentence without する?
Japanese Language Stack Exchange is a question and answer site for students, teachers, and linguists wanting to discuss the finer points of the Japanese language. It only takes a minute to sign up.Sign up to join this community
「(amount of money) + する」
"~~ costs (amount of money)"
That is probably the most common way of describing what a thing costs.
"I think it would cost at least 10 dollars."
You could say just about the same thing without using 「する」, but it will not sound nearly as natural. For instance, you could say:
I would be shocked if they did not teach 「(amount of money) + する」 in Japanese-as-a-foreign-language, seriously. It is an expression we use on a daily basis.