I don't understand with what right trader Joe's can prohibit somebody from reselling their products. If he clearly states where he bought them from, and that he is not affiliated, and doesn't misuse their trademarks (impersonate them), it should be absolutely legal. A side remark, people often say how great the US / north America is for entrepreneurs, compared to (continental) Europe where there is a lot of red tape…
A lot of people are using the "I bought chips at Costco and resold them at a concession stand example". This is at least a little different. Say you owned Captainmuon Grocery and only sold private label Captainmuon Chips. Although demand is so high you could distribute your Chips to other groceries and retailers, you see greater value in driving traffic to your store through the exclusive distribution. Don't you have…
In property law, there is the concept of a restraint on alienation. In competition/anti-trust law, there is the concept of a post-sale restraint. The idea is simple: after you by the chips, they are yours and you can do with them what you want. Restricting resale also limits competition, which is bad for consumers. Whether this view trumps your freedom to contract is a legal question whose answer has varied over time.
Historically, such restraints were a problem for real property in England. An estate might have been held in "fee tail" to be passed on to heirs indefinitely. Society decided that land was not being effectively used in this way, so fee tails were broken by statute beginning in the 1800's. Your freedom to "devise by will" was limited in favor of the property right of alienation.
Software was traditionally sold to the end user, who could use or sell the product as he wished, subject to Copyright restrictions on making additional copies for distribution. Only recently did this property-like right erode in favour of the current norm where software is licensed under a plethora of contractual restrictions you may never have read (the EULA).