Have just seen this in my local Virgin Megastore. Not sure if there will be copies in others, but worth a look.
Cheapest elsewhere online is £7.93, but next cheapest after that is nearly £28!
Pitched as a gritty, hard-hitting crime drama series about a mob family, Kingpin invites inevitable comparisons with The Sopranos--the pilot episode is even directed by Sopranos alumnus Allen Coulter--but the basic premise is more a south-of-the-border Godfather, with Miguel Cadena (Yancey Arias) as the conflicted Michael Corleone-type character who finds himself inexorably but somewhat reluctantly taking charge of his family's Mexican drug cartel. Written and produced by David Mills, a graduate of NYPD Blue and Homicide: Life on the Street, the show has all the right credentials for a successful TV drama, combining a colourful ensemble cast and evocative locations on either side of the Rio Grande, but somehow it failed to find enough of an audience in the US to get beyond one season.
Seems that this boxset has been deleted, hence its limited availability!