Context

Potter and Blogger gz, in her latest post, tells of a cold day in a market hall, where she sold nothing.
This in the gift-buying season. Yes, it's cold, but not everybody is stuck in their burrow, waiting for spring.

Yet she sold nothing all day. Shivering, stomping feet, breath misting in the cold, and the pots to be packed up and all taken home again. Her pots? Take a look at her gallery pictures.

I commented to her:
"I'm very sorry to hear your sales woes.
That was the same stuff that demoralised me, packing up to go to a market or craft fair, and at the end of it, realising my sales had not paid the costs.

Context, context. Like you say, people devalue what they see in a market. Put the same pot on a pedestal in a white-painted gallery, and it's special, they understand that it has value, simply because of where it is.
Because people they think must somehow know more than them have elevated it.

How can we fix these skewed perceptions? Because the pot in the gallery is probably overvalued, just as the market undervalues. Where's the fair ground, the honest appraisal?
Who can do it? Who sets a value? We potters surely aren't the best judges of our own work.

Your experience led me to think of something I read quite a while ago.
Go here and read of an experiment:
http://www.washingtonpost.com/wp-dyn/content/article/2007/04/04/AR2007040401721.html
Imagine Shoji Hamada in Abergavenny.
"Well this one's not quite round, and the rim's uneven. Can I have it at half-price?"

 What do you think?

I leave you with a video, of world-renowned violinist Joshua Bell, playing in a subway station, on a three and a half million dollar stradivarius.
Three days earlier, he'd played to a packed house at the 2600  seat Boston's Symphony Hall, where seats were around $100.
Here, he took thirty two dollars in 45 minutes.

Yes, it was commuting time, we're time-constrained, but we have an acclaimed musician, and out of 1,097 passengers, only seven stopped to listen.
Context.
Perception of value.