Yes, the cost saving is immense.
I cut our steaks (both beef and lamb) by hand and freeze them. (We live in an apartment atm. No slicer space.)

I used to work in a butcher shop, and this guy would come and ask us to slice rump roast because he made his own jerky. I haven't tried that myself, but it sounded fun. (I'm not even sure rump roast is what you should optimally use lol. He grabbed what was cheap and not too lean like eye of round or too fatty like chuck roast.) Maybe you and your kids would have fun with that. Different flavors or something!

You may have done that before. I remember you salting lamb/mutton. I've never had salted or cured lamb, but that sounds tasty.