The U.S. immigrant visa application fees have changed as of April 13, 2012. The fee for Immediate Relative and family preference applications (processed on the basis of an approved I-600 or I-800 petition) decreased from $404 to $230. Adoptive parents submit the visa application and fee to the U.S. Embassy or Consulate in foreign country after receiving approval notice on the Form I-600 or I-800. The visa applicants must pay the fees in effect on the day of payment, not the day of visa interview. Therefore, anyone who has already paid the combined $404 fee will not receive a refund even if the fee decreased by the time of their visa interview.
Source: U.S. Department of State