Don't start! I began in 1980 when a box of 240-grain SWCs from Marksman Bullet Co. wouldn't stay on a paper plate at 50'. I weighed a handful and they were as much as 11 grains apart! Shortly after that, at a Houston Gun Show I found a four cavity Lyman 429421 with handles for $35, and off I went. A buddy's pot and a Lyman 45 sizer, and I was casting bullets that would shoot to an inch if I did my part.
Now, some 35 years later I am about $15K deep in casting, sizing, and lubing equipment. I have ~35 Hensley and Gibbs gang moulds in every size, shape and weight imaginable, several thousand lbs. of lead, alloy, and lino, and I own at least one mould for anything I load for (some 30+ cartridges)...
Over the years when times were hard I have sold some of my own hard cast to help pay the bills, and I have learned how to make what I cast fit my own application. But it has taken me 35 years and I am still learning.
But I have to admit: there is some sort of very sweet pleasure and self-satisfaction that comes from watching five projectiles you made yourself cluster into one ragged hole at 100 yards from your own handload.