What am I doing wrong ? Auto fares..

I travel to Chennai every 15 days. So I always deport from terminal 1 and land in Chennai terminal 4. I travel to tharamani, my IT park. But auto fares differs Tharamani to Terminal 1 - 200 rs Terminal 4 to tharamani - 900 rs So am I doing anything wrong ! Am I being scammed ? Or its reasonable, may be terminal 4 is far from tharamani than terminal 1!