Is it worth taking additional payment from the client for creating and maintaining a subdomain?

Question

Fintech

Hello. I would like to consult with regards to the next point.
There is one website under maintenance, about 1000 products.
Created by me, the client pays a monthly fixed amount for site maintenance after creation. The question is the following: the client asked to create a regional subdomain for the site to the city of N-sk of the format cityname.sitename.ru, before that there was no such practice; on the toaster they said that in fact this is a complete redesign of the site, respectively, this is a waste of time.
Prior to this, an agreement was concluded that all site maintenance services would be fixed, i.e. the price for edits will be the same regardless of edits, but there was no discussion about domains. Is it worth it to compensate for the time spent by increasing the price of service?
How do web studios solve this?
How much to evaluate the work, based on the fact that the price for the service is 2000 rubles, plus free hosting and domain?

Answer 1

Deal with the implementation first. All questions will then disappear by themselves.