It's not discrimination. It's just business. Thanks to deregulation, there is never a single set price for all passengers on a single plane. The airlines are within their rights to vary their fares in any way they see fit. You are never obliged to accept any price offer.
http://www.usatoday.com/story/travel...story/2021993/
Don't relentlessly flood a website with the same, or similar, searches. It indicates a high degree of probability that you have to travel on this route and/or dates. To encourage you to book, they may start to raise their prices.
All airlines charge the highest amount they think they can get away with. Don't display behaviour [a must-fly-this-route-on-these-dates flyer, rather than a casual browser] that gives them the signal to start raising prices. If you must "play around", use one of the pricetracker websites rather than dealing with the airline website directly.
Note also that airlines tend to (drastically) raise prices as the day of departure approaches. The cheapest tickets tend to have advance purchase requirements, so these cheap tickets just are no longer available after expiry of these advance purchase deadlines. Late-booked travel indicates business or other essential reasons for travel - meaning that the passenger will be prepared to pay more than a leisure traveller.