Ray J understands better than anyone why Farrah Abraham 's refusing to fight in a celebrity boxing match ... 'cause promoters can't keep their word in the money department.
We're told Ray J was all set to referee Farrah's fight with Nicole "Hoopz" Alexander, slated for November 10 in Atlantic City. Ray's team initially wanted $50k plus travel costs and security but the promoter, Damon Feldman, didn't have the cash, so Ray agreed to do it for $25k.
Problem is ... a few weeks ago Feldman and fight investor Samantha Goldberg came back to Ray and asked if he'd ref for less dough 'cause the event wasn't selling.