A good example of an Amarone, Barolo, or Brunello style wine will be pricey (if not extremely so) depending on who makes it. A decent Nebbiolo varietal wine (remember, Barolo is a style of Nebbiolo but not the only form of it) might be found at a decent price in some stores. I've actually had some decent Nero D'Avola wine that was in the $10-15 category. Not the best examples, mind you, but good enough to get a sense of how the varietal stands out. Chianti can be rather hit or miss, but there should be no shortage of examples available.
When you get to blends like a Super Tuscan, you're going to see variability because there is no standard how much Sangiovese, Merlot, Cabernet (or others) to blend. They are also not necessarily labeled a 'Super Tuscan'. The best Super Tuscan I've had was in a wine bar - the glass wasn't cheap, but it was the kind of wine that reminds you all at once why you love to drink wine to begin with. It was a little sad after it was all gone.
There are certain kits, however, that get thoroughly great reviews. Just about all the Super Tuscan-style blends, for example, seem to turn out well and are sought after. It's difficult to fit a specific commercial wine to a kit wine because they're inherently not the same. The grapes sourced do not come from the same locations. The production style can make a big impact, as well.