I was at an informal bourbon tasting last night that was pretty interesting. I don't have a very refined palate but one of the guys works at a liquor store and he's really into identifying the proof, mash bill, and all of that. There was a bunch of $50-$100 bottles on the table, a few $200-$300, and the most expensive was a Boss Hog at I guess around $500. The Boss Hog wasn't my favorite by any stretch so you can't guarantee a great pour just by spending a lot.
I can get Buffalo Trace for $27 anytime around here. It's not a daily drinker for me but I use it for cocktails and I keep a bottle in reserve at camp in case I run out of the good stuff. One of the guys brought a Buffalo Trace store pick that was completely different. It punched way above it's weight and easily beat most $50 bottles. If I could find a batch like that, I'd buy it by the case.
To show how much variation there can be between bottles, the guy from the liquor store brought 4 different bottles of 4 Roses single barrel. As I understand it, most of the major brands take the exceptional barrels and set them aside to be sold at a premium or under a different label. Most of the average barrels get blended together to give you the flavor you expect from Woodford, Elijah Craig, or whatever. As the name implies, single barrels aren't blended. These 4 Roses were store picks so they had more info on the label than you'd see on a typical bottle on the shelf (I didn't even know their are different strains of yeast). One of the 4 Roses I really liked, one was pretty good, and two I didn't like at all. So the moral of the story is when someone recommends a particular bourbon, esp. if it's a single barrel, what they have in their glass might be completely different from what you bring home from the store.