Second hand PC peripherals? (UK)

When I'm looking for second hand guitar stuff I have a couple of places I look (PreLoved, Gumtree etc)

Was wondering if theres something like that for PC's? I'm wanting to build something later in the year, a second hand screen or mechanical keyboard/mouse would be a good way to save a bit of cash.

Anyone know of any sites like that for the UK?

*edit* or any Forums worth having a look at?

thanks!

@HapiJoel: Here are a couple I use.

Facebook Group

This was a forum but recently changed to classy ads

OCUK have a great community and a members market where once you have a 1000 posts you can take part.

Great, thanks KB! A good place to start.

EBay or any Facebook groups in your area that sell second hand stuff.

Really EBay is probably best just filter search to uk only