>I bought mine second-hand for about £100 in 2018. They’ve only got cheaper since then.

You'll be surprised. Due to surge in popularity within the last few years, in part thanks to youtubers, it's gotten hard finding old ThinkPads at this price, let alone cheaper. They've gone from their function over form and low used cost due to corporate surplus as their main appeal, to being geek-y lifestyle objects, not much different than Apple products for the mainstream. They're great machines but paying ~£150 for 10yo system, not even with great specs, is laughable.