1) you need a manufacturing ffl. the ffl is dependant on zoning, covenants, etc. If you don't live out in the sticks, you'll most likely need a commercial address.
2) you need high liability insurance (1 million minimum)
3) you need a bona-fide business (including tax id number, license, permits, etc). This has to be able to fly in your county, city, state.
4) Good idea to have a lawyer draw everything up and keep on retainer
5) Pending where you live, some places have ordinances/restrictions against x amount of powder storage (aka you might need to build a specific powder shelter, which is a good idea anyway if you're loading on a large scale)
6) Shipping cost $$$ due to hazmat requirements (this is for components as well as finished product)
If you're willing to invest a lot of time and money, it's worth it. If you just want to buy a press and sell some on the side, I highly recommend against that idea, as you could lose everything from someone else's negligence.