Welcome to the club... Best of luck! One thing, you might want to be sure that the 20 is your maximum and that if someone bids more, you will feel that they overbid. Also, you might want to have an odd amount eg. 20.47 or some other odd number. Just a thought.. Also while you are waiting for your first snipe, you might want to read the help tab and then bid groups. It is the icing on the cake.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .