Clearly, you've never been to Japan ;-) We've got $50 grapes! And that's for one grape... not a bunch... But I think you are correct that most North Americans especially are geared toward buying the cheapest produce available, often regardless of quality or production methods. I think it's slowly been changing over the years, but people still baulk at paying prices that would sustain small family farms without imported cheap labour. However, every time this kind of discussions come up, I feel it necessary to point out that vast majority of cost in food production is distribution, not production. This is due to the practical monopoly on food distribution that some companies have. You could actually raise the production price a pretty hefty amount without affecting the final price terribly if you regulated the distribution. Of course, what would the poor Cargill's do? They wouldn't be able to have swimming pools full of money. That won't do...

People said similar things about cotton before slavery was abolished. The world managed to survive.

People will absolutely pay $5 for avocados if that's what the price goes to. Avocados are among the easier things to pick though, so this doesn't really apply to them.

Tomatoes seem to cost about $3 at my local grocery store and are not nearly as good as avocados.

Have you ever been to brunch in San Francisco?

The cost of the raw food is 10-15% of the price of a meal. (Source: my wife ran a popular restaurant for 4 years.)

Then grow less labor intensive things.