I purchased a module that worked fine on most sites and even on one of my own sites. However, it wasn't working on another site and I worked with support for a couple weeks to try to pin down the problem. The were very helpful but finally determined that it might be related to something in my site and would require me to purchase a couple of hours to fix it. I agreed and the did their research and determined that if they made a small change to their module it would fix the issue. They then issued me a refund for the amount I paid for the service because they were able to fix it in their code. I felt that they were very helpful all the way through the process and very honest after i had paid them to do the fix. It is difficult to handle troubleshooting a module when everyone's system is so different and I have great confidence in purchasing modules and working with BCS in the future.