Slightly off-topic, but if you genuinely think that there's no such thing as high-end wine, I feel a little sorry for you. Surely you can tell the difference between the Budweiser/Calsberg-type beer and beer from an independent brewery? If so, then surely you can imagine the same might be true of wine? I get that the fact that some bottles cost thousands may offend some people's sensibilities, but this hardly covers the wine mainstream and is usually down to intangibles that go beyond the wine itself, just like a piece of art.
It's certainly the case, of course, that while there's a big gap between a $10 and a $50 bottle of wine, naturally the gains for price points above that get incremental pretty quickly in much the same manner as TVs — is a TV that costs $9,000 over four times as good as a $2,000 model?
Wine experts often stumble on double-blind tests, sure, but then again, so do audiophiles trying to differentiate lossy and lossless audio.