Under the Single Market arrangements, if you are travelling to Austria directly from another EU country, you do not need to go through a Red or Green channel.
Duty free allowances on goods bought within the EU ceased on 1 July 1999.
You can buy as much as you want to bring back from Austria provided you can prove that it is for personal, rather than commercial use. Acceptable amounts for personal consumption:
Tobacco products: 800 cigarettes, 400 cigarillos, 200 cigars, 1kg of smoking tobacco Alcoholic drinks: 10 liters of spirits, 20 liters of fortified wine, 90 liters of wine and 110 liters of beer.
NB: Passengers under 17 are not entitled to bring in alcoholic drinks or tobacco goods.
Value Added Tax is charged on most goods bought in shops in Austria and obtaining relief from VAT can save you money.

NB: Not all shops operate the Retail Export Scheme, and those that do often set a minimum purchase level.

The appropriate form (U34) is completed in full at the time of purchase. You must present the form to Customs at the final point of departure from the EU and have your goods available for inspection.

NB: Visitors leaving Austria for a final destination within the EU are not eligible to receive VAT refunds under the scheme.