I think when thinking about the price you need to consider the quality of the product and the consideration the establishement takes for our environment.
A great example of this is my preferred chippy, the Town Street Fryer. They will wrap your purchase however you request but commonly, or if to 'eat now' your food comes in a container - these are bio-degradeable and cause no long term impact if they end up as litter, or if they end up on land fill. They can also keep tabs on (if) how much litter is generated if customers throw packaging on the floor - I see nothing from the Town Street Fryer anywhere in the village - I say this with confidence because I regularly litter pick the area with the Marple Bridge Association.
Quality of product - what does the menu say?.... Hopefully like at the Town Street Fryer the fish is named on the menu boards - for example COD... or ..HADDOCK... watch out next time your in a chippy - if the menu simply states... 'fish' or 'white fish' the chances are the establishment are using something known as Panga... or Vietnamiese Cat Fish - this comes from fish wholesalers at a very, very cheap price and a profitable alternative to Cod. The fish is farmed from polluted rivers and typically lives on sewage - although nothing is proven there are many horror stories about this poor substitute.
One comment I found on Panga read:
"What appears is shocking. Horror stories of it originating from a highly polluted Mekong river, containing high level poisons, being frozen in contaminated river water and injected with hormones derived from urine. So there it was, a ranting, ‘don’t even go there’ article in the making, a nauseus feeling from the thought of what I’d eaten, and most recently, uneaten fillets in the garbage."
Think I'll have fish and chips for tea!
Peace Out.