In the basement food halls of Japan’s ritzy department stores you’ll find some of the world’s most expensive fruit. High-end specimens produced for the domestic gift market that can fetch eye-watering prices.

A single melon can sell for upwards of 15,000 yen (around A$200), a bunch of 15 or so grapes for 8,000 yen (around A$105), and premium white strawberries for 3,000 yen (A$40) each.

Earlier this year, two Yubari King melons from Sapporo sold at auction for 5 million yen – nearly A$70,000. (You can’t read too much into that price, however. Just like the record-breaking tuna auctions in Tokyo, hugely inflated first-of-season auction prices are usually about rival food corporations bidding to trump competitors for the resulting free media coverage.)

Explanations for the high prices of premium Japanese fruit usually focus on the labour that goes into its production.

Shizuoka’s famed Crown muskmelons are tended by hand for 100 days. Only a single fruit is allowed to grow on each vine, concentrating nutrients. They’re rubbed with gloved hands to stimulate even growth and sweetness. On sunny days they’re fitted with caps to prevent sunburn, and when harvested they’re graded on shape and skin quality as one might for pearls. Perfectly round melons free from blemishes fetch the highest prices.

Production costs aside, the important question is perhaps not why these fruits are so expensive, but why we find the prices so surprising?

Some of us will pay hundreds of dollars for a meal that has been tricked up by a chef for a few hours, but baulk at the same money for fruit that has been tended by a farmer for months.

These views have history. In the western world, the perceived value of produce has been shaped by the British agricultural revolution of the 17th to 19th centuries, and the green revolution of the 1950s. These two periods saw dramatic increases in crop yields, leading to much lower prices.

Most importantly, the effects of the green revolution shifted a larger share of the agricultural production for western nations to the developing world. Subsistence farming gave way to offshore commercial monocultures for processing and export.

Food production that was once a part of daily life became hidden behind a corporate veil. The value of our food became linked not with its place in our culture, but with its supermarket price tag.

In cultures where cuisine developed together with agriculture before intensive farming, ingredients hold a higher status.

In the Asian household I grew up in, we were told to finish our food not because children in Africa were starving, but because idiomatically every grain of rice represented a bead of sweat on a farmer’s brow.

Separating our culture and cuisine from agriculture has consequences beyond surprise at the cost of a melon. What we choose to eat and the value we ascribe to it is a question now more frequently answered by commerce than by nature.

A square watermelon sits in a department store in Tokyo. They sell for about US$80. Photograph: Koichi Kamoshida/Getty Images

Proponents of more sustainable alternatives to industrial farming often suggest that the price of food (particularly meat, but also fruits and vegetables) should be higher to account for the economic externalities of that system such as health and environmental costs. That such an approach could increasingly move natural foods out of the financial reach of lower-income households shows there are no easy solutions.

One of the key drivers of the British agricultural revolution was discovering that growing turnips and clover could replenish soils better than allowing fields to lie fallow over winter. Animals could be fed on both, so production increased. It led to a boom in turnip recipes in Britain and celebrated products such as spring lamb from ewes well-fed over winter.

These days our tastemakers are more likely to be chefs and Instagrammers than farmers. What we choose to eat is driven by ideas that are no longer rooted in the ground. If we all want to eat quinoa we can’t grow and avocados we can’t store there are environmental and social consequences that follow.

In Britain, spring lamb is no longer a product of 18th century field rotations. To meet demand, Australian and New Zealand hogget is shipped from the other side of the world to be served on-brand rather than in-season.

Of course $200 melons are hardly what we would consider sustainable commercial farming, but that we find it so hard to see high value in produce is telling.

I tried one of those very expensive melons once. It was the best melon I have ever tasted.