When I first started my interest in reptiles I was only young. At that stage of my life I had little or no skills and did not understand the requirements of the wonderful creatures so I did not keep them effectively. We just kept the local lizards, so the cage temperature was not an issue.
I rekindled my desire later in life but I also had mortgages, the cost of raising a family and the daily costs of living to contend with. A reptile was expensive enough, without adding the costs of retail cages and accessories. So I built my own. It saved me a lot of money.
You do need some basic tools but the money you save by making it yourself will allow you to purchase some of those tools that help make the cage. The remainder can go into accessories so that for the cost of a basic cage with nothing else you can make a cage, get some tools and the cage accessories and still have money left over. That