There I was in the produce section of the grocery store when I passed a bunch of interesting boxes – Mushroom Mini Farms. They even had two different brands. These are oyster mushrooms, ready to grow. I bought a box on impulse, being careful not to look at the price (I didn’t want to know). So I’ve followed the instructions and I’ll report back when I see mushrooms.
27th Street 
My understanding of the mushroom kits is that they do indeed produce mushrooms as advertised. The issue is that you dont get quite enough mushrooms to cover the cost of the kit compared to just buying the mushrooms at the store. What makes them interesting is the fun of growing yer own mushrooms. But you arent going to save cash with a kit. Having said that, you dont need a kit to grow oyster mushrooms. Once you have cropped your kit you can set up a so it yourself sort of deal using things like sawdust or shredded paper as substrate and inoculate it with mycellium from the kit and keep the project going without the need to shell out for another expensive kit. Oyster mushrooms are apparently particularly easy to grow and the internet is loaded with instruction for growing them.