It will never be a cheap option, but now there is a spray foam business for sale. The product is very good, and I recommend it to anyone who is looking for a spray foam product, regardless of what it is that the business sells. The spray foam is very thin, so you have to use it very sparingly. The foam will eventually wear off, and you will eventually have to re-spray your room.
This is exactly the kind of business you’d expect from a game like this. A guy who is looking to make a living from spray foam products has just been approached by a guy who is looking to buy a spray foam business. Sounds like a plan, right? Actually, the whole thing is a bit shady, because the business was apparently started by a friend of someone who had left the company behind.