iPad with 3G support went on sale last Friday and as always iFixit has posted iPad 3G teardown showing all the components of the new tablet. Not much has changed internally when compared to the iPad WiFi model, except addition of 3G chipset and supporting antennas. Apple has added two antennas for cell reception and one antenna for GPS. Apple uses Infineon 337S3754 PMB 8878 X-Gold IC for cell reception and Broadcom BCM4750UBG single-chip AGPS solution for GPS.

After seeing the teardown the main question that arises is why is Apple charging $130 for the 3G upgrade. Price of Infineon chip is around $13, price of Broadcom chip is around $3, price for supporting chipset and antennas is around $10 bring the total to $26 only for the upgrade. Even if you consider 100 percent profit margin for the upgrade it shouldn’t cost more than $52.

Analysts are predicting that Apple sold about 300,000 iPad 3G units on the launch weekend. Gene Munster of Piper Jaffray believes Apple has sold over 1 million iPads now. He also said supply of iPad 3G were limited on the launch weekend as 49 out of 50 stores he surveyed were sold out of the iPad 3G by Sunday.

In the last iPad 3G related news, iLounge has posted battery tests results for iPad 3G model. Apple claims iPad 3G offers 9 hours battery life and iLounge tests showed that Apple is almost right, as iPad achieved 8 hours and 38 minutes of battery life in their test.