It's fairly common for the girl to just negotiate a package price for the whole production if there are multiple things to consider.
For example, if the company tries to knock her scene price down, she's not likely to give them a break on the dialogue. But if she's the star of the movie with 2 or 3 scenes at a high price, sometimes the dialogue is for free. Again, it varies for each individual girl. I wouldn't able to tell you what a top girl like Jenna or Chloe would ask for the days when they are only on a set for acting.

However, if it's ONLY a cameo, and no sex is being done or paid for in the movie, it's standard to pay anywhere from $50 - $500 depending on the size of the part and the popularity of the girl.

Finally, girls look at getting a box cover differently too. Some girls say, OK this is going to get me more publicity, so if they give me the cover, I'll show up for the cover photo shoot for free. Others know that being in the movie will help the company more than them, so they charge for doing the cover shoot.

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