The music stores that I have been discussing mostly sell used CDs for $8 and less.
Another point which has not been stressed is the uninviting nature of indie record stores for a lot of people. Many of them have music fanatics working as clerks, who either lacked social skills when they started work, or lost their social skills while working at the store. My wife refuses to shop at indie stores, for example, because the clerks are rude, and ridicule her without cause. She also finds the "funky" nature of the carpet, restrooms, furnishings and decor to be real turnoffs--she does not find them to be quaint or interesting or atmospheric.
I think that the days of the hippie or alternative rock influenced indie music store may be dwindling fast.
An interesting phenomenon is the rise of Half Price Books, a chain which started as a single indie shop in Texas, but now has dozens of stores in about half of the U.S. I have been to three of their stores. They are all brightly lit, clean, and painted white inside, and kept spotless and organized. They carry publisher's overstocks of books, CDs and DVDs/videos, plus whatever people bring in off the street to sell. They have good selection, low prices, and many music gems--imports, box sets (including Propers) and other rare and obscure stuff. They have a discount section where jazz CDs I want to get are priced at $1 or $3. They have interesting vinyl music sections. The selection of music is close to what the long time indie stores are stocking--in some ways the Half Price Books music selection is superior. This is not a sterile environment, because the selection is surprisingly deep and unusual.
The Half Price Book stores are usually quite busy, including a lot of customers who have never set foot in any of the indie book stores or music stores that I have frequented over the years. During virtually any visit, I have seen people bringing in large boxes full of books and CDs to sell. "Ordinary people", who are not hip enough to make their way to the long time indie music stores, flock to the store in droves. They have a formula that really works.
I have picked up many jazz biographies, children's books, and CDs at Half Price Books, for ridiculously low prices. For example, a new, sealed 2CD set of Shorty Rogers, "Sweetheart of Sigmund Freud", for $1.00. It sells for over $20 at online sources.