Golly, $999.00. That seems to be a lot of $$ for cutting slots. We have a large floor model Enco, but I still usually do my slots myself. It's not really hard to mark a piece of material, drill several holes (use a sharp metal working chisel to mark where the punch marks will go, perfect line-up that way) then take some very inexpensive files (Lowes, about 5 or 6 in one $19.00 pack, all kinds of surfaces, last a good while, the name says Nickelson, but is surely a Western rim product. There are flats, curved, round, triangular, square, and something else).
Sometimes I think that it takes me longer to set up and cut a tang slot with the Enco mill, than to do it by hand. Hey, I'm the type that even likes to sand, so I'm a hopeless case anyway!