At no point did I say that you are worth whatever someone pays you.  That is not a statement you will ever hear me make.  Personal worth should not be determined solely by how much money a person makes.  

What I said is you're worth whatever you can get.  A person's market value, for whatever skill they can bring to the table, is determined by the market for that skill or talent.  A player who makes $10 million dollars a year's services are worth $10 million dollars a year, because someone was willing to pay it.  Basic free market capitalism.  

Just because someone isn't willing to pay a school teacher millions of dollars a year has no bearing on what kind of a human being they are.  However, since no one is willing to pay them those millions, their skills are not as valuable as those of a ballplayer, ergo, their market value is less.  Whatever someone is willing to pay you do whatever it is you do is how much your services are worth.  If people decide you aren't producing at a rate commensurate with the pay scale, then the worth of your services goes down, because you cannot receive the same price for them.  

Very simple, supply and demand economics.  It has nothing to do with what kind of a human being someone is.  Not that complicated.  

"social worth"? seriously? well, how about this. there are only several hundred people in the world, out of 6 billion, who are capable of playing in the Major Leagues. of those few hundred, there are only a handful who are capable of commanding truly large salaries (the A-Rods and Santanas).

there are millions of school teachers in the world. in fact, teaching children is something that almost anyone can do, so long as they have something approaching average intelligence. in fact, if the student is capable enough, he will probably teach himself much more through self-study than a typical teacher would, at least when he gets past the very first years of his education (this is certainly true of me; i was "home-schooled," which means that i taught myself, until college, and i am currently pursuing a Ph.D. i learned much more on my own than most of school-attending friends ever got from their teachers, and many of them attended expensive private/prep schools).

that is not to disparage teachers: they are performing a service. but even the best teachers can only provide that service to a handful of people at a time. baseball players can provide their services to millions of people simultaneously, regardless of age or school district.

so baseball players "deserve" to be rewarded much more than teachers, since exponentially more people buy their services than do from a single, individual teacher.

now, in the aggregate, we spend much, much more on teachers than on baseball players. in 2003, public school teachers alone (K-12) made ~ $140bn. that represented about 1/3 of total public school funding. that number has surely gone up since then. in 2007, even after all the "salary inflation" we keep hearing about, MLB player salaries were $2.4bn.

but the real truth is this: what someone is "worth" -- their value -- can be measured by the market. in fact, that is the only way for such valuations to be made independently. otherwise, we're all just spouting individual opinions. in one sense, of course, we are all equally valuable. but in another real sense, we're not. my wife is "worth" much more to me than she is to you. Johan Santana is "worth" much more to the Mets than he is to the Cardinals.

and there is nothing at all wrong with that.