If you literally have money to burn until the market turns around then have at it. From my experience, $500,000 in equipment will get you going and keep your production levels up.You can do it with less, however that will allow you to produce from mixed range brass to loaded ammunition at fairly high rates on a regular production schedule. You spend less on equipment by using pre sorted / processed brass **cough cough I know a guy** The cost of the equipment is one thing, the cost of components is a whole other animal.
9mm for example. Camdex loaders run about 4,400 pieces per hour. You start looking at 40 hour production week. I will round down to 35 hours to make it more realistic.
176,000 Gross output
150,000 Net output
1.5 to 2 drums of 9mm brass per week
30 cases of primers
100 pounds of powder
150,000 projectiles.
Ballpark math in my head says $35,000 in material per week. Under current market conditions, I doubt you could pay your bills off of one machine as the market right now is very, very tight.
Pro tip - Two machines is one machine, and one machine is none. When I spec contracts, I will typically only allow 75% utilization rate of what my actual capacity is.
If you are looking for components, Ganderite's experience holds true. If you are loading new ammunition then you can order components in bulk from manufacturers.
If you want range brass in significant quantities of common calibers, within Canada you pretty much have Western Metal and myself. There may be others, however otherwise you have to bring it in out of the USA.
"Domestic" powder and primers typically is brokered through Lawry or Higginsons. Unless you are buying really large quantities whereas you can talk directly to General Dynamics - St. Mark's Powder.