There’s a pair of Cary Audio 805s on USAudio Mart for $4,800, retail was $9,000; a pair of 211 monos for $8,000, retail $24,000, they’re monsters; a Cary 845SEI Integrated on ebay @ $4,350, and a pair of Cary CAD 300SE Signatures for $2,900. So yeah, $5,000 is about right.
Keep in mind the KR 300BXLS will set you back $1,200-$1,400 and will only reach full output with correct transformers running 450v+ on the plates. I own a Cary 300SEI LX that runs the KR XLS. It’ll eat regular 300bs like a tiger eats steak! Mine came with Shuguang 300b-Z that tested at 30/80 on a B&K, definitely past their prime. I bought a pair of KR XLS from the factory and wow! Great sounding amp driving Klipsch Heresy’s, Focal 716S and Vienna Acoustics Haydn’s. (I have way too many pairs of speakers.)
i also have a ChiFi 845 amp driven by regular 300bs and I love the sound signature of the 845. All the midrange warmth of a 300b, with lovely highs and strong, punchy bass, something the 300b lacks (except the KR XLS, it outputs 20wpc in the LX.) Also driving high sensitivity Klipsch and Focals. BTW the Shuguang 845B is a great economical 845 replacement, as is the 845-T Nature series. NOS 845s are $$$$$.
i’m a Dennis Had fan, founder and former owner of Cary Audio and now builds little SET/SEP amps under the Inspire brand. I have one of those too, KT-88. I’ve read where he said the 805 was his best design at Cary. Make an offer!