There is another thread regarding this general topic, but I will give you a synopsis. Girls make between $500 and $1000 a scene in general, new and ugly girls can make a bit less, spectacular girls or established stars doing a first anal, IR, bondage, etc. can make a bit more. I have heard that contract girls from the likes of Wicked, Adam & Eve and Vivid can make up to $80K annually for 12-15 sex scenes per year, some actual acting with scripts in the movies and a couple of promotional trips a month to conventions like AEE. As contract girls usually are in features and not gonzo, the sex is tamer -- usually no anal, condoms are worn quite often, the girls have a bit more choice in who they fuck. A lot of established porn girls are actually doing porn to get their name out there and making more off of feature performances in strip clubs than what they make performing in porn movies.
Before you say "lucky girls", remember that they have to pay their own medical bills, $150 plus a month for mandatory monthly STD testing, provide their own clothing and some have to pay managers a percentage of income. They also may have to pay double social security tax and pay thousands in tax accounting fees each year due to being "self-employed" (self-employed FICA and Medicare tax together is currently 13.3% right off the top), paid on a 1099 basis and not a W-2 basis (unless she is a contract star).

[Link]