In all honesty I am glad I spent $1200.00 on mine. There is no way I could have engineered, bought all the materials, and with my time factored in built one as nice as the Roto 2000 I own.
If I ever need a second one (which I do, but storage when both are not being used is a floor hog in my mind) I will just buy another one even though I have one to copy sitting right here.
Just my 2c