Costs will depend upon the country you are applying to and the visa type. Normally there will be a visa fee that you will have to pay in the migrating country’s currency.
An applicant will have to bear the other costs like migration agent fees, notary charges, courier charges, English language test charges, nomination and additional authorities’ fees.
In a few instances like an application for Parent Migration they might ask for a security deposit as a part of the assurance of support.