We are using Medisoft v17 with revenue management direct module. It cost us a little less than 2k. The Network Professional Version (the version you can run on multiple computers across your network) might cost you double that. We upgraded to v17 in order to meet the ANSI 5010 requirements. Required ICD-10 compliance in (probably) coming in Oct 2014. Medisoft v18 will not be ready for ICD-10 (
source), so we'll have to shell out some more money for v19 or possibly switch to another PM/billing software.
Medisoft is supposed to interface with AC, but I haven't attempted to avail myself of the interface. Double data entry isn't too bad. Depending on the workflow of your office, it can even be beneficial. I know it helps me catch errors, and I think it even saves the doctor some time (eg he doesn't always have to find the correct dX in the AC database; someone else can add it to the summary sheet afterwards).