The notion that better products must be more expensive is simply human psychology at work ("Is healthy food expensive because we expect it to be?"; Jan 10).

Under perfect market conditions where everyone possesses all the relevant information on products, more money should buy better quality.

But market conditions are never ideal and consumers may be ignorant or misled.

A mainly vegetarian diet with lots of legumes and nuts, washed down with tap water, is far less expensive than a predominantly meat diet layered with cheesy or exotically named sauces, and consumed with expensive alcohol or sugared soda.

There is also no strong conclusive evidence pointing towards expensive organic produce being superior to normal vegetables.

Should we also pay more simply because food is labelled non-genetically modified, when the jury is still out on genetically modified food?

No matter how much we are led to believe one type of food is superior to another, it is grilling, barbecuing or deep frying that makes an expensive food far less healthy than the steamed or braised cheaper variant.

It is worthwhile dosing ourselves with branded expensive medicines, as they provide better therapeutic efficacy than most generics.

It is also worthwhile to pay more for certified UV protection sunglasses, rather than trusting a fake label stuck on a cheap pair of sunglasses.

But for food, cheaper is not necessarily worse, especially if the cooking method is taken into consideration.

Yik Keng Yeong (Dr)