I have recently tried NSO's ordering system which was the nsohelpline.com. This system aims for convenience and for those citizens who are a busybee. This in fact delivers our certificates at our doorsteps. However, the downside was that it costs more than what is normally charge. 
For this transaction, I have ordered a copy of NSO certified marriage certificate which cost me Php 350 compared to what is normally charge of Php 140 plus say Php 20 charge if we ever get it from SM.
The rates from NSOhelpline (http://www.nsohelpline.com/) are inclusive of processing and delivery fee. Birth certificates, marriage certificates and death certificates costs at Php 350 per copy while CENOMAR costs at Php 450 per copy.
Payments can be via bancnet online, any metrobank branch, bancnet atm or selected bayad centers nationwide.
Delivery is usually within 2 - 3 working days upon receipt of payment. I got my marriage certificate on the 2nd working day via Air21.
