Run the other way!! I bought the "teacher's" version (the "good one") for a whole lot more than my present machine. In the 2-1/2 years I ran the Singer, it was in the shop twice. The third time I just bought a new Sears machine, rather than throw good money after bad. When it was open, you could see that the "commercial quality" parts were just plastic. The one I had was made in Brazil.
The Sew & serge cutter is just a cheepie attachment that looks to rickety to be of any use.