Hi,
I think your partner can suggest you this cost, also you can refer the below link
Perpetual
You have bought the Dynamics 365 Business Central licence, it’s yours forever and, as long as you pay the annual maintenance fee (known as BREP in the Microsoft world), you are also entitled to access the latest versions. With a perpetual licence you have a set number of users, which of course you can add to, but if you ever choose to remove users then you would have to re-buy them in the future.
If you stop paying the annual maintenance fee you are also prevented from amending your Dynamics 365 Business Central licence, i.e. adding more designers, more users or objects.
www.the365people.com/.../licensing-and-pricing
akkomplish.com/.../
