Why Why why

Hi , I am wondering why does YBA gear are sell so dirt cheap on audiogon ( like a 7000$ retail amp who sold for 2000$) Because I am planing to buy a yba amp but since they sell for really low does that mean they are peice of crap ? I already own a YBA 2 preamp and im really pleased ( feeding a old Marantz 250 Amp and my mini utopia ) Do you have any Advice of what I can use for the amp preamp combinaison to take the best out of my Mini utopia ?

Thanks in advance.
im using a YBA2 pre amp with a Bryston 4BST power amp and the combo works great....i also have a YBACD1 which is the icing on the cake.
A lot of YBA gear is at or near the Class A Stereophile list.
YBA amps are fantastic, extremely well made and great sound. There is no reason to stay away from them on the used market. I once demoed a 2HCDT and was blown away by the power delivery of this amp especially in the bass...rock solid!
That is, if you're married to solid state. Well designed tube amps will surpass solid state designs in dimensionalty and 'real-ness' on acoustic instruments and voice.