Alpha Wolf

You respect and even admire Godzilla for his abilities, but you're not a damn idiot! When Godzilla comes to kick ass, he goes into overkill. You don't want to be anywhere on the island when he arrives. You ask Moreau for your money.

"Alright Moreau, you said I could have my reward in cash, I'll be taking it now seeing as my work here is done."
"What?! You haven't done anything!" Moreau says.
"The hell I didn't, I got Godzilla to come here. He'll solve your Martian problem."
"Okay there's two things wrong with that statement. First of all YOU still aren't personally doing anything. Second of all Godzilla is Gil's cousin not yours, if anything he gets credit for this before you!"
"Yeah!" Gil remarks.
"That may be, but I'm the one who convinced Godzilla to come here! Gil was too busy stuttering and apologizing."
"Godzilla's not even here yet! I'm not paying you anything; you can wait until after he gets rid of the Martians."

Looks like Moreau isn't parting with anything until after the job is completed, but if you wait until after Godzilla does his thing there won't be anything left on the island to part with and that's assuming you can find some place to lay low to avoid the sheer destruction that's sure to come. (Even though Moreau seems to be ignorant of what's about to occur to his Utopia)