I bought a kit a few years ago. They advert said the kit came with a growth chamber. The chamber turned out to be the cardboard box the supplies came in.
I would do some research and buy the components yourself. You can get everything you need in one day, and you will save money.
You don't need a kit. Just watch "Let's Grow Mushrooms" on YouTube a few times and buy the stuff you need off the shelf. On eBay search "mushroom substrate" if you want to buy jars ready to go. But this stuff is no harder than baking a cake.