Whilst this doesn't beat my last build for amount of wood used; it probably wins the janky award.
A quick run down. Ether mining rig. Basic CPU, RAM and HDD. The only RX570's I could find in stock (I would have liked 7 cards, but beggars can't be choosers. Six was all Ebuyer had available). Dual PSU's were cheaper than one decent 1000W+ supply. Just had to use a little adaptor to get it to work. Initially bought the wrong motherboard (seen in photos), until I realised it had only 3 PCIe slots, as old PCI doesn't work for this use. Got a better replacement on ebay, nice and cheap! And of course, a £4 shoe rack... Total came to around £1400.
Mining ETH @ ~29.3MH/s and 112W per card. 175MH/s total. Sometimes dual mining ETH and Siacoin, but bumps power up to over 140W per card (which is kinda worth it, but a little unstable at times due to the extra heat and stress).
Let's hope I make my money back before ETH mining has its day!