phoenix gold titanium 500.4

Greetings! Newbie to the forum here, so please forgive me in advance for any transgressions... I have a Phoenix Gold Titanium 500.4 amp possibly for sale, and am testing the waters for its value. It hasn't been in use for over seven years, but worked perfectly when it was last hooked up and has been stored in a dry, temperate room in its original packaging ever since. It never had any technical problems, was always properly wired, and is in literally perfect cosmetic condition. No scratches, no scuffs, literally perfect. Comes with all original packaging, documentation, and a new LP44 low-pass gain control knob. I love this amp -- hence why I hung on to it for so long -- but it's clear I won't be putting it to good use anytime soon. So, assuming it still works flawlessly, how much is this baby worth?

Well I see you already have it listed on the bay for $400

Indeed I have; jumped the gun last night and posted it. But if anyone would like to make an offer I'm open to all comers...