I’d like to point out that, for some reason, 0.065″ wall thickness 304 stainless steel tubes are about half the price of 0.050″ ones, at least at speedymetals.com (http://www.speedymetals.com/c-8276-round-tube.aspx?thickness=1). They seem to be the lowest price I could find – a quarter per inch or like $10 for 4′. 0.050″ on the other hand is $0.48 per inch, $19 for 4′.
I ordered custom cuts from them as I’m building an odd size 27″ x 40″ (to match a space under my desk where my MPCNC would have to be stored between uses). A bit more expensive than buying whole-feet size but beats having to invest in a tube-cutting tool and cut yourself.
Shipping was $20 though.