The painting is way more than $400. I don't even think its for sale anywhere. I think you must be talking about a print on Canvas or a lithograph. That is a numbered copy and its limited to 2,500 copies.
Start saving!! LOL 
It really is a nice picture!
You can get an unframed lithograph for $135.00
Signed Edition Cert.
16x20 Paper Lithograph Yes 2,500 Yes Unframed $135.00