It really just depends on your practice.  Number of preparers, number of returns, types of returns, number of different state returns, etc.  Be thinking of where you are right now vs. where you want to be in 5 or 10 years.

The JoA annual survey results just came out last month, see the article here:

https://www.journalofaccountancy.com/issues/2021/sep/tax-software-survey.html

Rick