The ideas shown by both Yobrosew and Alikigirl made my jaw drop! This is taking the idea of an extension table to brand new heights - er, that is widths! It's an excellent solution to the problem of wanting the machine level with the surrounding surface without having to spring for a special piece of furniture, as long as your chair is a comfortable height.
What I use for my main machine is an old sewing cabinet that came with an insert that fits my 1972 Bernina machine. When I got the new Singer I had a handyman cut a piece of quarter-inch acrylic to fit it. I made a template for him by taping some typing paper together.
I want to second what KSellers said about checking Craigslist. That's where I found my sewing cabinet, and of course it was much, much less than a new one. They turn up now and then. One time I saw a to-die-for cabinet and matching cutting table with storage, very reasonably priced, but alas, I didn't have room for them. It's definitely worth having a look.