An unreliable product

After three years of moderate use of the printer, printing becomes very low. I called the customer service dHP and I am told that we must change the printer and we head to commercial service that offers me to exchange the product at a higher price than trade .
What a wonderful product !!! Everything is going so well since the era of sustainable management, it is not possible to change at HP printheads. Where is the idea of ​​sustainable development at HP? Similarly, is it normal for the HP loyal customer pays more for a product at HP?
On second thought before buying HP