Yes. sort of.
No one can bid lower than your opening price.
So do not set your opening price lower than you would be content to receive.
But.
Members can send Best Offers.
These can be lower than your opening price.
You are not required to accept these. You can even set the Best Offer option to automatically reject best offers lower than you are willing to consider.
You can also go to Manage Bidders on the Site Map and Block bidders from whom you do not want to receive bids. This Block remains until you remove it and is supposed to be on all the IDs used by that member.
