When I first started using a Dremel tool I always got the thin grinding discs. Later I found out they sell another disc that's twice as thick. They last a lot longer.
Although I prefer using good tools, I like to remember that people used to have a lot of really impressive skills back in the old days, before you could pop into Harbor Freight and buy a metal lathe or milling machine. My brother in law has some tools handed down from his great great grandfather, who moved to Ohio from Germany in the 1800s. He was a clock maker. One of the tools is a table saw, which he built himself. It's about half the size of a two-slice toaster. He cut out the wooden parts to build the saw, which would then cut nicely mitered pieces for clocks. Judging from his work on the table saw, I think he could have made perfect clocks without it, but he built the saw to speed production. The saw was powered by a small steam engine, which he also built. I've seen the steam engine, but I'm pretty sure it went to another one of the brothers in my brother in law's family.