Billing – ProRata vs Direct Amount

I have been working on this forum and I want to thank everyone for their great contribution.

A question I thought related to your billing settings, considering Prorata vs. direct billing, which would you recommend?

I like the idea of ​​Pro-rat, as it provides more supervision and control, knowing that all clients will be billed for their related hosting services on a specific day of the month.

However, I do not want customers not to understand when paying and see an amount of $ 5 per month, but then they charge $ 6.50 on their first bill (due to apportionment).

I would appreciate any ideas, thanks.