Also, if you're confident enough in your coding skills to attach the code you wrote to a motorized vehicle with sharp, rapidly spinning blades attached to it.
Exactly, you can do a lot of amazing things with less money than certain things sell for. Most people spend that premium because the time required to build X for cheaper isn't worth it in the long run. (unless, like you said, its apart of someones interest or hobby)
When I was in college, I had more time than money, so it made sense to do these DIY things. Now that I have kids and a good income, I have more money than time, so I tend towards buying solutions to easily solvable problems. It sometimes makes me sad that I don't get to tinker, but I'd rather spend time with the kids.
Hopefully as they get older, we can combine spending time together and tinkering!