Most useless Constitutional amendment ever?

On the danger of specifying numbers in laws, when numbers can change.

While researching something else, I came across the Seventh amendment:

In suits at common law, where the value in controversy shall exceed twenty dollars, the right of trial by jury shall be preserved, and no fact tried by a jury, shall be otherwise reexamined in any court of the United States, than according to the rules of the common law.

Is this the most useless Constitutional amendment ever? Not because its sentiments are wrong or out-moded, but because $20 these days is worth peanuts?

And, incidentally, does this amendment say anything other than a) trial by jury is important, and shall happen in all moderately-important cases, and b) you can't use legislative or executive powers to reverse a jury trial?