Bangalore is a city of Tamil Nadu while Hyderabad is the capital of Andhra Pradesh. There are many similarities between these two metropolitan cities. For instance both these cities are home to many private companies especially software and hence many software professionals work in these two cities. Thus it goes without saying that these professionals need to commute between these two states frequently for the purpose of work and for this reason there are many flight operators offering cheap Bangalore to Hyderabad flights and vice versa.
All you would need to do is find a website over the Internet that would provide a list of all the flight operators that commute between these two cities along with the schedules and the price list. You can then compare the timings as well as the prices and choose a flight to book your ticket that would suit your budget as well as requirements. It takes around an hour and a half for flights to Bangalore to reach from Hyderabad and there are direct flights offered by Air India, Jet Airways, SpiceJet and IndiGo. The ticket fare is reasonable anyhow but if you want the tickets at an even cheaper price, try to book a little in advance.
Although it is difficult to plan in advance if you are traveling for work but if you are fortunate enough to book your tickets during a sale period offered by any of the operators, you would be able to fly almost at a nominal cost. There are buses and trains to and from Hyderabad and Bangalore as well but flights would take you to your destination faster. And if you can get a flight ticket at the cost of a train reservation, of course it would be a practical and wise idea to choose the flight over train, especially if you are traveling for work.