Why do you need to have “scamming people” as a business model instead of selling those machines as what they are?
They’re born for office use and are still perfect for office use. They’re not and they’re never been gaming machines. You’re trying to deceive those people that they just know “Intel i7 is good”, but they don’t know that a 1st gen Intel i7 is worse than a 10th gen Intel i3. They’ll immediately return it as soon as they discover it can’t run even old games at 720p 30fps
Find which line you like (optiplex, thinkcentre, HP), stock only similar computers and sell them to small businesses, 5-6 years old machines are still overkill for accounting and email.
I resell old thinkcentres with a 100% margin without any kind of lie or omission and customers are happy and buy again. Then because I only stock the same stuff I have plenty of spare parts and I can give fast replacement