New Laptop

Hello to everyone! I am thinking whether to buy or not to a new Laptop.
At the moment I have a machine with intel core i3 6th generation processor and 4 GB DDR4 RAM, but it's not completely free because of intel ME and proprietary BIOS and WIFI. In your opinion is reasonable to spend money to buy an used completely free laptop?
I don't have a lot of money to spend so I'm thinking to buy a laptop from minifree. But if I buy it how long will it last? I mean it's already an old machine, it is more o less 10 years that it's been used, and I am worried that it will end to work within 2 or 3 years and also I am worried about high temperatures that are common on old machine. Then, it's half less performing than my current laptop in terms of CPU. What would you recommend?