I have, back when dollars were redemable in gold (pre 1963ish).
In order to compare prices you need something of constant value. The most accepted something is gold, gold however is not perfect since it too is subject to supply/demand inflation/deflation however it is the best benchmark of real wealth we've got so I think I will use it until a better benchmark comes arround.
No, the only meaningful comparison of price is what I have or what I can earn. The rest is only theoritical discusion. For me the most compariable price is what it take in time for me to earn. That is my real price; what I have to give up to have it.