What does the current study prove? Some wines cost more?

What needs to be studied is if there is a correlation between price amd consumer preference. As far as I can tell, this was not an effort to do that, but rather to prove the obvious: you can't taste price. This is true for any kind of food.

Can you look at two pieces of art and tell which is ore expensive? No. Is better art more expensive? Sometimes, usually yes, and often eventually. Same can be said for wine. Price is a product of demand, demand depends on information and information distribution. Both products are small batch and highly personal, so price quality correlations will be less accurate and change over time.