Also forgot to mention that the support cost for Praxis is 14.9% x Licensing Costs yearly.
1 Provider - $1500
2 Providers - $2250
3 Providers - $3000 (sweet spot relative to AC)
etc.

So in terms of support, pretty close.

AC does have a sizable support fee as well. Flat rate though. No discount on additional providers. 1000/yr. This is where Praxis may be better when it comes to larger practices.

Personally, I think that is a little much considering all of the providers might have one server and one database. Should be discounted when sharing the same database.