Depends.
I don't think the MLR is billed as some massive compeition, it seems to be generally a steady comp more focused on targeting college student players and local club players with the odd low budget foreign player.
They are only allowed to play 5 non American players per match, and looking at the players who are in the league the big names are
Kane Thompson (New Orleans)
Ben foden (New York)
Paddy Ryan (San diego)
Vainikolo (utah)
That's in the whole league.
It really does seem a very organic comp aiming for the grassroots rather than trying to aim to high too quick.
I think the salary cap is only $450,000 - $500,000 and many prob have some sort of sponsorship benefits, maybe working for a local company as well.
I do also think unions and clubs will be looking at the comp and potentially loan out players to try and help build brands once it becomes established.