If you want to know the proper way to build a real putting green, let me know. I was involved with the construction of the new golf course at Purdue in 1997, and was on the crew that did most of the greens work. The course was a multi-million dollar project, designed by Pete Dye. FYI, Pete designed the courses at Kohler, WI, the Brickyard Crossing at the Indianapolis Motor Speedway, and many others that I can't think of right now.
To do a real one the right way won't be cheap, but it will be a helluva green.
I had a good experience with all pro putting greens. They have a web site (www.allprogreen.com) . They were easy to work with and were happy to answer any questions. I installed 3 synthetic greens for one of my customers and they turned out great, nice add on to your business.
I would recommend synthetic turf over natural turf for a putting green - unless a bucks up customer wants one.
After building and maintaining golf courses for over fifteen years ( I was one of the project managers for the golf course D Felix mentions), you do not need to install a USGA spec'd green for sole owner or residential use. A native soil, or push up green will work very well with limited soil admenments, in fact check with your local chapter of the USGA or equivalent for more info.
I sure gotta go along with the synthetic route. The USGA and PGA have specific designs for greens and a install is not gonna be cheep. But the real expense is going to be in maintenance. Wait till you have to keep bent grass alive at 3/16 on south slope at 90d on a high sky day. Not to mention daily mowing with reel mowers. When I meet a PGA or USGA Grounds Superintendent, I take my hat off. These guys really know their stuff.