I built this PC a few months ago, and find I don't use it very often. When I do use it, it's not for anything which needs this much firepower. So I'd like to sell it, buy something significantly cheaper, and put the difference towards our gigantic mortgage.

Specs:

AMD Ryzen 5 1600X
Gigabyte GA-AB350-Gaming 3
G.SKILL Trident Z Series 16GB (2 x 8GB) DDR4 3200Mhz CL16 1.35v
Samsung 960 Evo 250GB M.2 (2280),NVMe SSD
EVGA SuperNOVA 650W G3 80+ Gold Full Modular Power supply
EVGA GeForce GTX 1080 Ti SC Black Edition, 11 GB GDDR5X
Cooler Master Hyper 212 LED Turbo CPU Cooler
Phanteks Eclipse P400 Tempered Glass Mid Tower Case Black Edition (No PSU) tempered glass with 10 colour RGB cycle
Microsoft Windows Home 10 64bit OEM Eng Intl

I added a couple of extra fans in the front (also Phanteks) to help with airflow through the case and maintain positive pressure.

Just checked the prices of the components, and if you were to buy the same today you would be looking at around $3150, without assembly. Could probably shop around and get that down a little, but make me an offer. :)

Like I said, I'm looking to downgrade and bank the difference - so if you're thinking of upgrading from something a couple of years old, I'd certainly consider including that in the exchange.