I agree that it is a serger. I bought an old one at a yard sale this summer for $30.00. Mine works great but it is tricky to thread. I'm glad that I got the book with mine as it's probably a 'no name' one and I can't find anything about it on the net. Mine is probably too old/or off brand to be on the net now. I think it just might have been made before computers were so popular, or something like that.
Are you going to get it? What are they asking for it? Just curious.