I have a Sage 300 customer who just implemented Square 9. They started off telling me they had integrated with 300 before but during the process it became obvious they had not as I had to create views for them to read Sage 300 data, then had to write a program to check their output files before they get imported, and am about to get an order for a program to finish automating the import of AP invoices. I have also heard that the processing in Square9 is not as seamless as advertised, and for a company that normally pays their bills promptly it has caused some headaches.
So since I had not brought them in it was good for my revenue, but I wouldn't give any fixed price for ""assisting Square9 with implementation""...