I've never seen a more negative bunch of guys in my life than the naysayers here on CGN. You can't do this, you'll never be able to afford that, no one will pay the price, etc... If you guys are all right then how do Wolf in the East and BDX in the west seem to stay in business? And not just stay in business, but be so busy that they have a huge backlog of orders. Not to mention that they sell their commercially reloaded ammo for prices that are well below the price of normal commercial ammo. It can and has been done and it quite profitable for those who don't get bogged down in the negativity here on CGN...
Now that being said, if your plan is to also manufacture the components, then the investment will be far more substantial and you will need to do some real world research and conduct a proper feasibility study. It may or may not be a feasible business, but I can assure you that almost no one here on CGN will know for sure.
As as for the components, there are countries other then the US that you can buy them from if you are worries about US export restrictions...