Applying for a fiance visa to the United States involves several steps with filing fees to be paid along the way.
Step 1: Filing the fiance petition (I-129F): $340 Fee to US Department of Homeland Security
Step 2: Once the fiance petition is approved, one needs to file for the visa application and pay for the visa application fee: $240 paid to the Consulate/Embassy where the applicant is going to have their visa interview. The visa applicant will also need to undergo a medical exam and that fee varies - usually between $100-300, paid to the clinic where the exam is performed. This fee does not include the cost of any vaccinations that the applicant might need to get.
Step 3: After the couple gets married, the foreign national fiance will be eligible to apply to adjust his/or her status and obtain legal permanent residency. The filing fee for Adjustment of Status is $1070 (including the fee for biometrics, or fingerprints, to be taken), paid to the US Department of Homeland Security.
If you are considering filing for a fiance visa for your spouse, you should consult with an immigration attorney.