"The stores where your chances of finding something nice will always be in the areas where the incomes are the highest. "
I disagree. The wealthy are too busy with their snouts in the stock-market to listen to music. Their knowledge is:Fleetwood Mac,Sabbath,Zep and Young. (That is if they know even that much.)
My friend used to tune pianos and was often in the mansions of the rich. He would snoop at their bookshelfs or music collections when no one was looking. Conclusion: the rich have abysmal taste. They like coffee-table "books" and music that has been funnelled down their throats. They do not seek the music on their own.
(Also, they are cheap:Generally I find better things/prices in garage sales of the non-rich.)
I said previously that the religious have no musical taste. Neither do the rich, the sports addicts or the audiofools.