Re: "Magic Moulder"?
Having made a few of my own moldings at considerable less cost than manufactured goods, I'm not as pessimistic as my fellow cohorts. An important distinction in "cheaper" is that the actual cost of materials can be far less, however, when you factor in the amount of time it will take you to set up your machines and make the moldings, as well as any special tooling required, your cost savings diminishes rapidly. Your time has value as well, the question is, can you produce your own moldings at the same or better quality than you can buy.
IMHO, you're going to have a tough time holding a piece of material into a table saw to cut crown. When you consider the size of the cut and the dimension of the material, you're looking at multiple passes and probably a few different set-ups to achieve the finished product.
If you really want to make your own moldings I'd recommend investing in either a molding cutter or a shaper. These tools are designed specifically for this purpose and do the job much more safely than it can be done on a tablesaw.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!