Seriously I had to pay 75$ to get one recently, which was painful but I needed it.
Same here but with 10 units. Almost 100$ each.
What for? I'm sure you have some older computers that run much better that you already have in your house. An APU would trounce it. Pi feel like netbooks of desktop computers, the new ones get extremely hot, I would expect it to require a heavy heatsink and constantly spinning fan if you tried this.