Try Craigslist. Go here to find the city closest to you and check em out
https://geo.craigslist.org/iso/gb
Corsair 500R Case, H110 Hydro, 1200AX PSU, Asus Maximus Hero VI MB, Intel 4770K CPU, Gigabyte GPU GV-N98TWF3OC-6GD, G-Skill Trident 2400MHz 32GB, Crucial M500 960GB SSD, Seagate 6TB HDD x2, Creative SBZ to Denon AVR-4311ci - Infinity Primus 5.1 w/Klipsch Sub XW-300d, HP ZR30w 30" S-IPS LCD, W10 64bit