It's 45,000. There are 45 quests in total. If you google dirty league event there's a page with the quest details for pussy market and named events, but if you don't spend any money, you will not be able to complete all of the quests because the quests got ridiculous. You simply won't have the time to complete all the quests. It may be possible if you play this game 24/7 but that's not realistics.
Edit: If you scroll up, Deercoffee posts details of the quests and the cumulative silver coins that you can earn by completing the quests. After the last quest you will have 45,000 from completing all quests alone.