I priced mine up for a self build vs prebuild and there wasn't much saved. Plus buying pre-built gave me 5 yrs warranty. Even for accidental damage. The company I bought from want you to open the case and are happy for upgrades while still covering the parts you bought originally.
Link to what I own; https://www.chillblast.com/chillblast-v10-gtx-1070-gaming-pc-lease-for-1-week-system-only-.html#product-details-tab-tab353
I ended up with a palit 1070. I paid total £1069 but I had to add a Wi-Fi card. Otherwise it was £1036
Chillblast seem a top drawer company. Fella was glad to sit on the phone while I picked his brains. I had an issue with the power lead not quite sitting in the socket so if the PC was moved it would switch off. Not a big deal at I wouldn't be moving it but with the cables sometimes tangling I was worried it'd tug it. They just sent me a new one within 24hrs.