What computers are those in the picture? I'm totally new to crypto currency mining and I have a picture where there is a rack of computers mining cryptocurrencies (supposedly). I'd like to know what computers are those and maybe availability and pricing.

I tried to ask on meta about whether this question is suitable to Bitcoin SE, but I got a message saying that I need at least 5 points of reputation :(

This is the picture I'm talking about:
These are Application Specific Integrated Circuit(s), a computer that is designed for Bitcoin mining. PCs used to mine too, but when FPGAs released (later ASICs released), mining with a PC wouldn't be efficient because of competing ASICs (and electricity fees).

Currently Bitmain (shop.bitmain.com) is the most preferred ASIC manufacturer, but it looks like it may not stay so, in a 6-12 months. (The most popular ASIC is Antminer S9, $1500, currently.)