I waited untill I found what I wanted and then deposited $100 to start bidding. You can deposit less and you can always make a deposit at any time to increase the amount you are allowed to bid. Transactions are instant using PayPal. If you decide to remove money from your OKShon account you can do so at any time. Check the Fee page (the "Fee" button in the menu bar) to get an idea of how the charges work.