Why so much for Quattro

Off the top of my head, I think (emphasis on think) that quattro requires a number of upgrades, like engine (?), DSG, etc. that are included in the price. Some research would be helpful though.

its so much for the Quttro cause its not all the easy to make and the huge computer systems that control the audi all wheel systems. Also with the audis the quttro systems its the most advanced and the all wheel drive system also controls the esp and the abs so it takes a lot to built these huge systems. So thats y the quttro is so much more!

any car company that has a awd version will cost significantly more than the 2wd versions.

$1900 difference for the A3 2.0 FWD vs A3 2.0 Quattro isn't a whole lot of money, when you consider the amount of additional hardware that it entails. As for Audi "charging so much", well, Mercedes charges $1800 more for the C300 with 4-matic, so Audi's cost seems fair.