20. Is there a limit on the amount a candidate can contribute to their own election campaign?

Law on Financing of Political Entities, Article 11, paragraph 4; and Article 5, paragraph 1.1.

11.4. Candidates of political subjects cannot accept any donation outside the rules established through this law for the financing of political subjects. No donation can be made directly to the candidate, but must go through the political entity, respecting the provisions of this law.
5.1. Political Subjects are allowed to receive contribution from: 1.1. natural persons in the amount not exceeding two thousand (2.000) Euro per calendar year.

Candidates of political entities are not allowed to receive direct donations; instead, all financial transactions must go through the exclusive account of the political entity. Still, if the candidates of political parties donate to their parties, than the limits as per natural persons apply.