Any recommendations for a good inexpensive estimating software program?
Take a look at Co-Construct. It is a cloud based project management tool that integrates all aspects of the project life cycle and even integrates into any accounting software you may have. Fairly inexpensive for all the functionality.
There are some great CRM’s out there if you are just looking to manage a service type process. I can’t remember any names off the top of my head but many of them charge by the job deliverables. What I mean by this is they charge 1.50 for an Estimate, Sales Order, and Invoice. This is a good way to go since you only pay for what you use.