Sellers, both the individual and the institution, have their own reasons to engage in the behavior they do. Presuming no one is engaged in outright dishonesty or law-breaking, they can sell you anything they can get you to buy.
If you walked into a car dealership and said, "I want to buy a car." And the salesman points to a premium vehicle and says, "That Cadillac is $50,000." And you take out your checkbook and write a check, you would have no cause for complaint if you found out the next day they were selling a nearly identical Buick for $40,000.
A smart shopper needs to be informed, and ask specific questions. "What is the lowest priced seat in the orchestra?" "Are there any discounts available right now that you can tell me about?" "Are there better seats available at this same price?"
Box office salespeople are SALES people. They should be friendly, answer pertinent questions truthfully, and do their honest best to get your butt in a seat. They would be failing their employers if they didn't try their hardest to sell to you. They should be honest, of course. And good salespeople work to match people with products they are likely to be pleased with. If someone inquires about any discounts available, I think the box office staff should recommend the least expensive seat. FWIW- I envision that in the relatively near future we will all buy tickets either online or from automated ticket kiosks, which will be the ultimate equalizer, since you will have the ability to see the seats available.