As far as I know, you have to pay $100 SEVIS fee and $100 visa application fee before the interview at the time of application submission. If you are issued a visa then you have to pay $200 visa issuance fee. Your case as funky said is still unclear. Better talk to the appropriate person. Visa issuance fees are based on reciprocity, and if you are a nepali citizen you are required to pay $200 visa issuance fee.