The Palingates blog claims the public university's alumni association will pay the former Alaska governor $75,000 in speaker fees and $18,000 in expenses.
The amount is reportedly more than double what Palin charged to speak at a local Republican Party event in Oregon.
State Sen. Leland Yee, D-San Francisco, says if that is true, Palin is gouging California students.
CSU Stanislaus insists the money is not coming out of the university's budget -- the alumni association is funded by private donations.
State Attorney General Jerry Brown has launched an investigation.