I have a good condition Schecter Diamond Series Demon 8-string. They're ~$500 now. Active pickups, really good condition. I was offered a customized VHT Special 6 Ultra with a 12" Jensen speaker from a 70's Fender twin reverb and a 50's blackplate 6v6 tube. Picture of the amp included. Is this a good deal?
From the looks of that wooden cabinet, this is a good deal only if you can touch, feel, inspect, and play through the amplifier before you make the trade. And it would have to sound REALLY good.
You would be ill-advised to make such a trade via long-distance (payPal and the mail).
Just a note; hand-wired VHT amplifiers that I find online cost much less than $500. And they are bound to be a lot lighter than a modified amp with a hand-built wooden cabinet. Weight IS a consideration when loading in and out of gigs.
One other concern; a Jensen speaker from the 1970's may have a nostalgic value, but it's doubtful that the cardboard cone still sounds as punchy and clear as a new Jensen speaker.
I am a moderator on two separate guitar web forums, and have been providing such valuation/trade advice for many years.