I wouldn't... (Score 1)

Simply because of support issues. If you build your own machine and something breaks, who do you call to replace the part? Most likely you'll be spending time and money troubleshooting broken hardware and buying replacement parts.

When you buy a pre-built system, yeah it's more expensive up front (and not as fun) but in the long run you'll save time and money, and a big headache on your part because of the time and money you'll save with proper warrantees and support. Think about how you will look if these machines start failing and you have to start scrambling...

After all, this is a business not a home project.