The basic differences are: Sage 100 Contractor is a (mostly) fully integrated system with best accounting practices built in. It does well if you can modify your company's workflow to match the system's workflow. Sage 300 is sold by the module and allows you to tailor the software to match your company's practice a little more easily. Because of this, there is a fairly large price difference between 100 Contractor and 300.

It really depends on what functionalities you're looking for in the system. Sage 300 tends to be a little more expansive when it comes to individual modules like estimating and project management, but each of those are individual modules. Sage 300 is better when it comes to inter-company transfers, because you can do that really easily in 300 where you would need to go into each company and make an individual entry in Sage 100 Contractor.

Thank you.