I bought my BabyGo for 99 dollars a few years ago, it came with one die cutter. I find my dies on eBay, and I usually only buy a die when I absolutely need one.
Right now mine is getting a workout. I am going through my scrap tubs and cutting out 4 and 5 inch squares, 2.5" squares, rectangles and a lot of triangles. This way if I need to whip up a few last minutes gifts I have plenty of scrappy shapes.