Aircel is offering iPhone 3GS for just Rs 9,999. With this you'll have to sign up for a Advance Rental of Rs 3,000 but you get equivalent benefits on the same thus keeping the cost of iPhone at just Rs 9,999 and that too at a time when Indian Rupee has gone to the dogs against USD.

Benefits of Rs 3,000 Advance Rental Plan in 3G Circles
Free 2GB of 3G HSPA Data every month for 12 Months.
After 2GB UNLIMITED Data Transfer at 128 Kbps
You can see the Circles where Aircel is operating its 3G network here.

Benefits of Rs 3,000 Advance Rental Plan in Non-3G Circles
Validity - 6 Months
Voice Calls - Free 1000 Local and National Minutes every Month
SMS - 2500 Local and STD
Data - UNLIMITED FREE 2G GPRS

I'd say this is a steal for iPhone Lovers. Go For it.