You can directly make a phone call to Sun (india) and enquire about certification voucher and you can also enquire about discounts and how to purchase. This is centered at Divyashree chambers, Shanti Nagar, Bangalore.
Contact Sun in India - General Enquiries
Speak directly with Sun
India Office (Toll Free): 1800-425-1234
India Office (Non-Toll Free): (91-80) 6693-0600
One more information: If you plan to attend "Sun Tech Days" event which is scheduled to happen at March 2010 Hyderabad (Not sure of Telungana Crisis), there you can get upto 30% discount on the vouchers. May be you can purchase one or more voucher ranging from 7500 to 10000, instead of 17,500. Dont forget to get your cheque book during the event for the purchase.