DIY is a poor method for saving money which is why I do it for the love of the craft rather than the monetary aspect.
Also time in one constraint that we all have to work with.
If you try for the monetary saving you will find yourself in a tricky situation because it’s just really hard to actually build something cheaper.
Economies of scale allow shops to buy materials at far cheaper wholesale prices. Automated machinery combined with overseas labor makes the costs of labor fairly low, and a sufficiently competitive market drives down the margin.
Buying the item will almost always be cheaper than buying the materials and making it yourself even though the quality may be lower though.
For people that want it to last forever this might be worth it, but for the majority of people out there they won’t use half the stuff they buy this year next year.
When you buy a pair of boots that are expect to last for life, it only refers to the upper portion. If you want to mix the two, consider buying a high-quality product and maintaining it. With boots the sole will need to be replaced but how often it needs it depends on how much you wear them.
I’ve seen them last a few years or a few months.
The upper portion will just need regular cleaning and conditioning, which you can do yourself in about 10 minutes with like $20 worth of supplies (that will last a long time).
This is turly taking care of your belongings and this is the case with anything that is of good quality.
I was taught to live by the rule that you don’t skimp on stuff that separates you from the ground. I buy the best shoes, tires, chairs, and mattresses I can afford.
It is a simple rule, but one that has served me well.
So leather work is a pretty expensive hobby/job. Most people including myself start with small easy projects that don’t require many tools, and gradually add more tools as needed. I’d estimate all the tools necessary to build a pair of boots would run at the bare minimum, $200-300 (or possibly more) not including the Landis 5 in 1 which could easily be upwards of $750.
Leather on top of that would initially be a couple hundred but that would last several pair.
Aside from amateurish boots I mostly build horse tack, gear and do some saddle repair.