It IS possible to grow mushrooms from dryed mushrooms. All you need is some sterile swabs and some sterile water. You dip the swab in the water and rub it on the lamellae (gills) and you will pick up plenty of spores. It only takes 2 of a compatible mating type. Mating type is analogous to sex, but mushrooms have up to 50 mating types. Men women attack helicopters cross dressers bulldozers and 45 more. This is the only way to get spores from some strains like the penis envy line. The gills are so tightly packed spores can't escape and they don't produce a sporeprint.
Another method I've had success with is cutting a piece of lamellar material and putting it on a supplemented agar petri dish. I built this laminar flow hood for right at $200 and it took me from struggling to grow anything to being able to clone any mushroom I found and bring it into cultivation. If you want to grow mushrooms in any serious capacity, you need this. I looked for a long time to build this for $200, but you could build this tomorrow for $400