You can start out fairly inexpensively like I did - get a lee lead pot for around $50 and the bullet mold of your choice - around $100 with the handles, and you are set to go. You can then swap the handles between molds to cut costs. You will need to size and lube the bullets using a hand sizer and pan lubing, or all in one shot using a lubrisizer. You can buy scrap lead from metal recyclers, but then you have unknown hardness, and may have to alloy it for correct hardness, which is a trial and error experience, and you need a hardness tester. Or you can buy the exact blend from Rotometals or Midway. You'll want to buy the Cast Bullet Handbook
to get you started. Its pretty much the holy grail of information that you'll need.I've been using an RCBS Promelt for some 30 years now. Much more expensive, but figuring the many thousands of bullets I've cast with it, its amortized out to pretty near nothing. I lucked into several thousand pounds of radioactive tracer cups that my old company scrapped (wrong size). It's nearly pure lead which is great for black powder, but I have to alloy it with linotype for the smokeless loads (you can get linotype from the same sources). I've finally worked up the perfect cast load for my Garand, and now it is hardly more expensive to shoot than my 10/22. There are two different types of cast bullets - plain base and gas checked. The plain based bullets are good for the pistols and very light rifle loads (less than 1200 feet per second). 1200 fps and above you need to used gas checked bullets - a small copper cup that is crimped to the base of the bullet to prevent gas cutting (and then leading of the barrel). Curiously having an alloy too hard will also lead the barrel, which is counter intuitive.
I haven't checked into casting my own bullets, though you now have me curious. With the lead ban, in effect how do you get the lead? I remember reading somewhere that we don't use lead in the tire weights anymore either. If we can still get lead, what does something like that cost to start? I am thinking for my 357,44 mags and maybe the 30 06. I heard if you shoot lead too fast you get some kind of fouling? Anyways that sure looks like a pretty round