Yup, as my original post said. But getting paid by MLB was a better deal regardless. The $400/weekly figure is actually the new rookie/short-season minimum salary, so those players are also getting paid better than they would be for playing affiliated baseball, since the payments began in March and those players usually don't start getting paid until their season starts.
I'm just so used to minor leaguers being paid so poorly, especially in the winter, that in my head the idea that MLB was only throwing them $400 a month seemed perfectly plausible.
If Indy ball pays and can play until the end of October that would add two months of work for some of these guys...unless the teams do something in AZ or Florida. Outlook doesn't seems so great for that right now though.
