As someone said...nothing new. You see many amps go like that...SigX is another good example of a used amp selling for nearly half it's value and those are fantastic amps. In fact it's my favorite VHT/Fryette and one of my favorite all around amps period. I see them at $1100 or $1200 and those are steals IMO.
My JVM is my favorite amp I've every owned. Since purchased I've literally not gassed for another amp and I've owned one since they first came out. I can get anything I want out of the amp. All subjective...I personally do not like the DSL but many guys love those things and I've heard amazing tones out of them. I just can't dial them in though. Everyone always wanted Marshall to make a modded amp...well the JVM is it IMO, the Orange channel to me is pure modded Marshall. Hidden jewel of the amp is the Crunch channel with an OD in the front, I can nail my 800 tone easy. Cleans are fantastic as well. Just my mileage.