That's right. It's 50/- for ATM Card per year.
Which has been replaced by new Classic / Silver VISA Debit Card nowadays.
The charge for card is 102/year. And card replacement charge is 204/-.
BTW, AFAIK, you have to replace the card if you want to get the new card. You can't keep both the cards. I faced the same issue while getting that new card. So I guess you can't waive off the replacement fees
Though this thing depends on bank to bank.
And regarding advantages, VISA and Master Card are international cards and accepted globally over local Maestro Card.
For more info visit :: STATE BANK OF INDIA :: Safe Banking With SBI ::. Google won't reveal much as SBI site is not designed for better SEO Manner. They uses frames probably
Navigate to sbi.co.in > Select Personal Banking from Quick Links (top left) > Services (on left pane) > Card (on left pane) > Debit Card (on left pane).
Everything is mentioned there.