Do I pay anything more when I win?

According to the USCIS site, Before being interviewed, each winning applicant must pay the Diversity Visa Lottery fee. For DV-2017 and DV-2016 applicants, this fee is $330 per person. This fee is nonrefundable, whether a visa is issued or not.
Fee payment procedures vary between different U.S. Embassies and Consulates. At most locations, you should make arrangements to pay your fees before the time of your interview by following the instructions of the U.S. Embassy or Consulate at which it will take place. A few U.S. Embassies and Consulates collect fees in the consular section at the time of your interview. Be sure you have looked at the specific instructions for the U.S. Embassy or Consulate at which you will be interviewed so that you can follow the appropriate procedures.
Other fees may apply to other parts of the process, such as medical exam fees, or local government fees to obtain certified copies of your records.

We do not and cannot ask for payments on behalf of any USA authority – the US DV Experts is a private entity and is not affiliated with the United States government in any way.