I read Big Papi's book, and the discrepancies in pay and the effect it had on team morale was one of the things that really irked him. He did not mind so much people on the team getting good offers, but it really irked him that the huge money went to free agents with no ties to the Sox. ( specifically Carl Crawford etc.) He wanted more respect given to loyal employees.
He's right, of course. There are three standards of pay in MLB; the amount you get initially (a mere 500 + grand per year (tongue firmly in cheek)), the amount you can eventually sign for if you are loyal to the team, and the amount you can get in free agency if you are deemed to be a valuable commodity. David Price is not worth more to the Sox than players earning less than half his salary. Then again, to get him we had to overpay, and the difference between the Sox with him and without him may have been winning the WS and not winning it. On the other hand, the discrepancy in salary becomes a problem when it is contract time for the comparatively underpaid players.
For years Papi was underpaid by the standards of baseball because he gave the team a hometown discount. It wasn't until after 2013 that he got Very few teams have the resources to sign their stars to the amount they can get in free agency, and with the luxury tax there is a penalty for doing so. What the Yankees did in the late 90s with their young stars they wanted to keep was pay them so much they would never become free agents. I would love to see a system put in place in which players would be paid according to value and that the formula for pay would be based on contribution to the team, with certain guarantees put in place for injury seasons etc. It will never happen, but it would be so much fairer.