EVDO in Jamshedpur

Hello mates,I am new to forum and i need a help from you mates.I was using airtel gprs since 4 years but now they are charging on usage basis which i cant afford.So what are the options for me now? how much i have to pay in evdo for UL?what are basic charges i need to deposit?Please let me know every expenses which i need to pay.I am currently jobless and not in position to afford more than 500-600 rs.regards