There are lots of things that can be done to save money on the homestead. (Homesteading is usually born out of a desire to be more frugal anyway)
One of the big things that I did was to house my rabbits in one large pen rather than individual cages. To begin with, I thought cages were sad because the rabbits don’t get regular interaction, but pens are much cheaper. I was putting them in a shed with a floor anyway, so I didn’t have to buy wire for the top, bottom, or separating sides. Just buying wire for the walls was much less expensive.
This is an experiment I’m trying out, and so far, it’s working.

These are some of the dried beans from my pantry. Instead of buying bean seeds, I did a seed test on these pintos to see if they would germinate. As you can see in the picture, they are! I plan to put them outside soon.
You can do the same thing with store-bought potatoes. I’ve never bought seed potatoes in my life, and that’s the one crop that always seems to grow well for me.
I also ferment my own veggies, too. Not as much as I used to, but that can save a lot of money, and it’s really healthy for most people (Sadly, I’m sensitive to histamines and can’t have much fermented food). Sauerkraut is extremely easy, but I’ve done kombucha, sourdough starter, wine, vinegar, and right now I’m trying out gf soy sauce.
I heard my dad say this, and it’s true: saving money on the homestead is mostly deciding that your projects will make money. If something isn’t making money, either change it or stop.
I realized the other day that my rabbits weren’t making money. Part of that’s because they haven’t made babies yet, but I could have been selling their poop all this time. They make plenty. I haven’t been doing that, but I’m going to start. I’m in the hole with them, money-wise, and I need to get out. The situation was completely brought on by ignorance. It won’t be hard to put the poop in a bag and put a post online, but I didn’t know I needed to. I decide whether they make money or not.
There are plenty more ways to save/make money on the homestead, but these are a few to start.