I read John Feinstein’s Where Nobody Knows Your Name: Life In the Minor Leagues of Baseball the other day.
Among other things, I learned that when a minor league player — that is, one without a major league contract — is called up, he is paid for each day at the rate of the minimum major league salary ($500,000 this season) divided by 180 days. A player called up for three days, for example, would be paid $8333.33 ($500,000 divided by 180 times 3). A typical AAA player is paid $2,150 a month (for the five month season), so a few days in the big league is quite a bonus.
At lower levels the pay is much less — “Most earn between $3,000 and $7,500 for a five-month season.” [In lawsuit minor leaguers charge they are members of 'working poor']
Major league players receive $100 a day for food on the road; minor league players $25. Minor league umpires are paid $1900-3500 a month (for five months).
In the higher minors, the players, manager and coaches are employed (and paid) by the major league team. The local franchise — for example, the Albuquerque Isotopes — controls and manages everything else, but not the baseball.