You might think so if you know schoolteachers only by reputation, but actually, they spend a ton on teaching materials. They will go to Barnes & Noble, scour the educational section and plunk down $200 without blinking.

Well, my wife is an elementary school teacher, and I promise she doesn't spend 200 at BN without blinking. She does spend some money, but not tons.

Most people in every profession fail at #1.

Hence why you need to find the ones that don't :)

Although once you start evaluating, you'll rapidly find there are plenty of markets that fit the bill. Golf. Soccer fans. Airplane enthusiasts (RC, amateur pilot and planespotter alike). PC building enthusiasts. Almost any business. Martial artists. Re-enactors and RenFaire enthusiasts. Almost all the alternative medicine areas. And that's just off the top of my head without mentioning any of the markets I'm actually considering entering one of these days.