I kinda made a post about this in another thread.
Basically the UFC spent ALOT and still spends alot of money building up fighters, advertising, sanctioning, building the sport basically...while someone like Gary Shaw, etc can get a name figher who recently left the UFC and ride their popularity.
Basically, UFC spent alot of money building them, Exite XC etc can use their investors money purely on the fighter...but then look at the undercard...the recent show at the playboy mansion, one guys purse was $500! lol. Lowest i see on UFC cards is $3000 for the nobodys