Can I buy an item (for example, a laptop) at Black Friday for $ 500 instead of $ 800, and later when the price returns to $ 800 for $ 750? As a new product
Nobody will take it off you. If you sell something as new and Origianalverpackt, many ask for the original invoice for warranty and then there's 500 euro on it, they will not get involved in the deal.
Of course you can. If it is a one-time action hardly anyone will suspect a commercial because profit-oriented action behind it. But:
You first have to find someone who wants to buy a product without warranty from a private person.
For the almost same price wants to pay as it is for only 50 euro more (at 800 euro not a big jump) including warranty is to be had.
You can already do that. Whether someone buys it is questionable. In addition, most people always want proof of purchase for a new product - for the guarantee. If they see that you have paid less than they, then it becomes critical to the sale.
OK thanks