30 years is about 5 years short. The Testors .21 was sitting in just about every hobby store in the early 70's. They were the cheapest engine in the store for their size. So when Testors decided they were not going to sell McCoy's (they didn't go under, just decided they were not going to sell flying models or accesorys), the remaining stock sold fast. Most were control line engines and usually owned by beginners. As such they soon met their demise in a crash, (thats what happened to mine). I am told they didn't last well but so what they were super cheap. There are still many around, but their value is so low nobody bothers to sell them.