A person, usually a person who is selling Real Estate (likely their own home) who thinks the value of thier holdings are the same as when the last 'bubble' in Real Estate happened. Currently, it would be the bubble of 2006 that they refer to. This person, this seller, thinks their home is worth today what it was at the height of the bubble. They are, deluded.
That seller is so crazy if he thinks that dump will command a price that high... he's a total Bubblehead.