> difference pretty well between a $5 and $20 bottle (hint: the $20 one is the one not loaded with sugar)

Wine loaded with sugar??? AFAIK, in a dry wine all the sugar is converted to alcohol- even in the case it's been added before the fermentation, which is still pretty rare, at least in major wine producing countries. That is definitely not the difference between a $5 and $20 bottle of wine (in Italy you can still get excellent wine for $5 a bottle if you buy it from the producer, btw).