As with everything, it’s a balance between quality and price. Finding the right product at the right price is the difficult bit.
Lately, as I get older, I look at items and wonder if it is best to buy a cheaper item and replace it rather than a more expensive one which I should keep. It does depend on the item obviously. But, keeping to the letterbox topic, I bought a reasonably cheap one - £20 on the basis I could buy six of them for the price of a more expensive one - quality may be reduced but, should my wife decide to change to another style/colour etc, it can be changed cheaply. My original letterbox lasted 20 years so six should last 120 years and I doubt I will be around to worry about the last few!