I can tell a difference sometimes. Sometimes the $10 wine is better, sometimes the $20. It all depends on how big the difference is, assuming the more expensive is better.
And the next question becomes: do you really want to become a wine expert? Do you want to risk knowing the difference between a $30 bottle and a $100 bottle - and wanting the $100 bottle?
Before I came to this forum I didn't have $500 boots and pens.
Sometimes I decide ignorance is bliss.