I think the best place for such information is the website of each winery. However this would take a long time!
As an approximation, low-price wine aimed at the international market is typically lower in acid and higher in (residual) sugar. However some great wines contain residual sugar (in the best cases masses of it - e.g. Tokaji, Sauternes, Trockenbeerenauslese)
Beyond that I think it depends so much on the grape/region that it's difficult to draw a conclusion
e.g. Great Primitivo/Zinfandel can be 15% alcohol, whereas few great Cabernet Sauvignon's are that strong
Planting density and grape yields are a good clue to quality, but can be misleading (especially planting density). I remember posting a question on yields on another forum http://www.wine-pages.com/cgi-bin2/ulti ... 1;t=002014
which investigated usefulness of yield information.
I think Robin's reference to the Italian site is a good one to follow, as the Italians are very good at posting this sort of information. Beyond that, I think it's worth reading some of the very technical wine studies text books, which would be very hard work! Perhaps some of the winemakers who post here could give some good pointers?