www.yourbillbuddy.com is an excellent site that can compare all the existing plans avaliable and match them to your usage profile. The thing I liked most about this site is that you can upload all your bills in pdf format and then can get recommendations on the basis of actual usage, not some fantastic data that you believe is your usage pattern. I have seen folks who are in the state of denial (or blissful ignorance) about their actual mobile phone usage. www.yourbillbuddy.com is the site for you whether you make local calls, STD calls or a mixture of the same.
www.yourbillbuddy.com seems to suggest I can save around 440/= a month if I switch to Reliance 399 plan. Let me give it a shot!