The economy shoulders go on sale fairly often too. You can get a single shoulder for about 18-20 bucks, plus shipping, when they are on sale. You will spend nearly that for a smaller piece too.
If you order from Tandy, you can pick up a few tools at the same time, that will make things go much better. A stitching groover, overstitch wheel set, skiver, gum t, dye, and an edge slicker. Also needles and thread.
For 75 bucks or so, you can be set up fairly well to start. You don't have to spend the money on the tools, but it will save you money on shipping later, and will save you time in building, and let you make things that you will like better due to their more finished look.