This
I got a refurb Lenovo (ex-business) laptop for £150. came with 12 months warranty, I use Libre office and it runs like a dream. It's like a big heavy brick though!
Definitely not this
I would save for a Mac (an air MacBook on Argos at the moment is £749 and if you take out the Argos card they sometimes send out money off vouchers a certain spend so you could get one as a great deal plus interest free on credit card).
Macbook is 5 times the price and will not be 5 times better or give you 5 times the money making returns.
My 3 year old Lenovo bought from new for £250 is running absolutely fine and has been since I got it. It does feel a bit cheap and plasticy and chunkier than the more expensive models but its does its job (matched betting, surveys, ebay, email, streaming and general internetting) perfectly.
As an aside. I think 2020 will be the first decade since the introduction of home computers that we will see a decline in the number of homes with proper desktop or laptop computers as more and more people rely solely on phones and ipads and smart TVs with various apps.
I work in a school and already most of the kids say the only thing they use a computer for is typing up their homework.
I much prefer a computer with a proper mouse and keyboard myself to squeezing a tiny phone screen in and out and doing the finger swipe thing.