If a kinda niche hobby becomes more popular temporarily, there's also the chance that waiting it out will score you some good barely-used gear for cheap as those that buy and try decide it's not for them.

Thats exactly what's happening in Germany with indoor weed growtents at the moment. We legalized homegrown weed in April, which caused a huge wave of people buying new equipment for double the regular price because of such high demand, and now suddenly people realize how much work it is and that small mistakes can easily ruin your harvest. So now the marked is slowly starting to be overflow with used equipment