Silverline Sonata II's are available used for $2500. Tremendous tube friendly speaker, it is 2 db more sensitive than the naia and extends 15 hertz lower in the bass- to 25 hertz. The effortless midrange is the highpoint of this speaker, but the bass is tight, controlled, and does not leave you craving a subwoofer.
http://www.soundstage.com/revequip/silverline_sonataii.htm
http://www.soundstage.com/revequip/silverline_sonataii.htm