Should selling price depend on product quality or on work to produce the product if both not in positive correlation? I am a Natural Science student and read a little about economics. I am not sure this question is related to economics or not, decided to give it a try.
Recently, I am looking for printing service. From more than one service providers, I got the details that, printing a page is more expensive than photocopying a page. I asked them why is that so, and they said because the quality from printing is better than the quality of photocopying (photocopying inevitably causes a little dislodgement, cannot be 100% same as the original). They confirmed that the inks and papers used for both are the same. This is what I replied: ''Raw materials required for both are equal, printing needs way less work than photocopying each page one by one, so I actually expect the price for printing to be at worst the same as photocopying if printing is not cheaper than photocopying.'' And I didn't hear back from them.
Who is right here?
If the shoppers are right and printing should cost more than photocopying, do you really want to penalise your customer for reducing you work?
If I am right and printing should cost less than photocopying, do the shoppers really want to give higher-quality product to customers at lower price?
Is there any economics theory for this and other similar everyday occurrence?
No one is &quot;right&quot; here, there is rarely a &quot;should&quot; in economics, it is not about morals.
When making a purchase, you are usually willing to pay an amount $x$ larger than the price $p$ which is larger than the cost $c$ it took to make the product/provide the service. You are arguing that price should only depend on cost. The store is arguing that if you are willing to pay more, they can charge more. Unless they have competition who undercuts them, they are right.
In the theoretical model of perfect competition, where there is a single type of product and firms face very strong competition the price would equal the average cost in the long run. I would argue the model does not apply here, competition is not perfect (if I am wrong, go to the competition). In case of imperfect competition it is normal to charge people whose demand is less elastic w.r.t. price more.

What you can do: pay them or find a better offer. If you are convinced that you are right, found a rival printing firm, undercut them and put them out of business.