I have a B8. Its a fine little enlarger. I can't think of anything on it I didn't like, nor did I ever think it was lacking in any respect. The only reason I don't use too much anymore is because I went to Large Format.
Last year, when I was thinking of selling it (which I talked myself out of) I did a price survey to get an idea of what it might be worth. If its in good shape, $100 is a heck of a deal.