To be honest I got into casting as a way to feed my 454 the bullets I wanted to shoot for a price way less than what I was paying for the same ones made commercially. They were $35'ish per hundred less shipping. Pick up two hundred and throw close to $12 in for shipping that was darned near a hundred bucks per order.
Now I already had some wheel weights I got for free, and the Lee 4-20 which I had purchased years before to pour up large surf weights with. So figuring in the cost of the mold and some gas checks I happily found on ebay, I added in around a hundred bucks for tools.
So I re-purposed the 4-20 to pour bullets, and with only 50# of wheel weight alloy I was able to pour up a little over 1100 of my own. Figuring in the mold and GC's at $100, and using the prices paid for the commercial only less shipping I saved close to $300 doing it myself. Even if I had purchased the 4-20 and the alloy, I would have still saved close to a hundred bucks with my initial #50 of wheel weights.
So in my mind yes for the calibers I shoot a lot it is well worth it, not to mention once you have the mold, and some alloy stashed back your set for when times get tough or even tougher then they are now. I might have gotten into it a bit more than some once I started pouring up HP's and working up the alloy I needed, but still I can now pour cast bullets in both solids and HP's for nearly all of my rifles and handguns so I do not feel it when things get tight.
As for buying bulk, I agree there is no substitute for when you can afford it. I did so with my brass, primers, powder, and jacketed bullets, so I am in pretty good shape with them as well. Even so, once your done with them, if there is a shortage or outage, I am still in fair shape for quite a while.
The casting thing has brought a whole new dimension to handloading as well. I now have loads which actually work as good or better than the jacketed loads I was using, but use less powder to do it, and also do not impart as much wear and tear on my guns as did the jacketed loads.
Sort of like buying a vehicle. While a Toyota Corolla, or F-150 works great for a lot of folks, I would have a hard time trying to pull my 16,000 pound tractor around with either when I need to move it. So I have a Ram 3500 which has more than enough under the hood and chassis to get the job done.