If you can't find anything cheaper, there's nothing wrong with cancelling the return trip. It happens all the time!
Be very careful when doing this. When I was working for American and also United Airlines we were told not to sell tickets to people that we knew would intentionally throw their return.
Here's why round trip "super savers" are cheaper than one ways.
"Super Saver" round trip tickets are extremely restricted. The tickets can only be changed once they are purchased for a huge fee. Also keep in mind that changing an outbound date may invalidate the ticket all together. MOST super saver fares must be purchased at least two weeks prior to departure and must include a Saturday night stayover. They are always ALWAYS non refundable but they are reusable which means after you pay the penalty fee you can use the difference to put toward a new ticket. They are also non transferrable which means the name on the ticket must match the ID of the person travelling. You cannot give the ticket away.
One way tickets are much higher priced because they are for the most part un-restricted. They are also completely refundable without penalty.
Also bereavement and military/gov't fares are higher because they are unrestricted.
When you purchase a plane ticket via telephone its the law the agent to whom you are speaking must tell you the basic "rules" of the fare. When purchasing tickets online be very careful to read the small print before actually purchasing because you may be shooting yourself in the foot if you find the ticket is unchangeable and totally restricted.
Air India has decent service for a good price and their change fees are a LOT cheaper than the other airlines. I changed one of their tickets a few years ago and it was just $25.00. Most airlines are charging at least $100.00 to change a ticket now.
To save money try to fly out of one major airport into another major airport. I live just 20 minutes from Birmingham International but I usually travel 2 hours down to Heathrow to save a fortune. I fly Air India into Chicago and then take another airline to the city Im travelling to. I usually buy those tickets in US Dollars on American Websites. American and United both have hubs in Chicago so you can usually get a decent fare pretty cheap out of Chicago.
Happy Flying!