baseballpapa ...
I do know that the coaching staff, the trainers, the conditioning guys are all employees of the MLB, not the MiLB team. So they are paid directly by the MLB club.
As far as costs (for minor leagues) to the club during the year, I will hazard a guess as to what costs are picked up by the MLB club:
In spring training,
(a) they don't pay a salary to the players but they do pay a per diem which varies depending on whether the player is living in the team hotel or not;
(b) they pay to keep the clubhouses open for many hours each day while the minor leaguers areworkikng out;
(c) they keep the training room open for the players who are rehabbing or need some TLC as they get ready for the year;
(d) they pay driving or flying expenses when the players leave for their assigned team;
(e) they pay hotel costs at the new town (my son's team covers hotels for 3 days as most players have arranged their housing before they leave spring training;
(f) they pay the coaching staff, team trainer, etc., and the costs associated with relocating to the assigned city (e.g., hotel, mileage, etc);
All this time in spring training, they are NOT making $$ from these teams in spring training. The MLB players are the draw for ST games and the stadiums get pretty full, so there may be some money there but I strongly suspect it doesn't pay all the costs.
During the regular season ...
(a) they pay salaries for the players, coaches, etc.
(b) they pay meal money when the team travels;
(c) they pay travel expenses (bus for everybody but MLB and AAA), hotels, etc.
(d) they pay for the front office staff to travel around the country to check on the minor league teams;
(e) they pay 'pro scouts' who travel around the country to scout the minor league players for other clubs (for trade purposes)