Yup. Been a commercial bullet caster and ammunition manufacturer for 3 years now.
The money is in the volume. In reality to be competitive you are going to make maybe 1-3 cents per bullet gross profit.
You certainly won't be rich and you won't even make much of a living at it.
The thought of the economy of making your own bullets triggers one to think they can make a lot of money selling them. I was a victim of that thought process too.
Let's take the hand caster with a Star sizer and Lar's lube into the picture. Foundry lead by the pallet is maybe $1.50/lb for 6/2 alloy. Let's cast some nominal 200gr SWC for the .45 ACP, H&G 68 type. 1,000 bullets is 28.57 or 29lbs for easy numbers. That will run a cost of $43.50/K. Figure 2 sticks of lube will run about $2, so our cost is up to $45.50/K. A guy with two Lee 6 bangers can do about 1,000 bullets an hour casting from 2 20lb Lee pots. Then sizing is about another hour. So 2 hours to cast and size 1,000 bullets. Bullet boxes will run you about 60 cents each to box up 500 bullets per box. Cost is now $46.70. Then running a label so your name and bullet type are on there along with your logo, probably 2 cents each to amortize ink usage.
OK, cost now is $46.72 for 1,000 bullets. Now you have to factor your labor. You check Missouri Bullet as they are one of the leading bullet makers on the Net. You decide to match their price, since the convenience of having them for sale locally with no shipping but sales tax might make them a bit more expensive in the long run, but the customers have their hands on it today.
Cost per 500 is $23.36 and you list your retail for bullets at $34/500 or $68/K. Your gross profit is $10.64/500 or $21.28/K. Yup. You're making about $10 per hour at retail consumer direct or a whopping 2.128 cents per bullet gross profit. You need to make room for resellers, so you take 15% off your retail price for dealers. Now your price is $28.90/500 or $57.80/K, with gross profit being $5.54/500 and $11.08/K, respectively. Nice. You're making a gnat's hair more than minimum wage as a self employed bullet making machine!
Now for the same price plus a bit of shipping they can get the same thing you make but from Missouri Bullet Company who cares if you're local?
If you are going to make any money you need to make serious volume and get your costs under control. To do volume required to stay profitable you can't cast by hand. That means spending $10,000+ on a commercial machine and a cool $8,000 more on a commercial sizer.
Even hand casting with a commercial sizer and collator will size faster than you can cast. If the machinery is idle, it's costing you money, not making you money.