Well, it isn't a matter of how powerful a laptop is. It just matters how many years will it live with you. Let me say something. I am using a laptop that I bought 6 years before and it is running windows10 with 4gigs of RAM.
My only general tip would be to buy a laptop that you can upgrade part by part. Make sure you can upgrade the RAM, make sure you can upgrade your HDD/SSD. Make sure you can upgrade the graphics (if provided).
And if people are providing i7 core powered laptop at cheaper rates, then don't buy those. They use faulty/junk processors or try every bit of nonsense to reduce the cost. Invest one time rather than servicing the laptop every time which would sum up to the grand total of the original cost of laptop.
From @xXAlphaManXx with