hey Shadow...good to hear from you... I'm one of th worst on price cause Ilove em so much that they are worth more to me...as a result I never both to sell anything cause I'd want too much for them.
Here's my 2 cents worth..and all are welcome to disagree...
Cosmetics is what its all about with our beloved kustoms...if an amp is free of cig burns, tears, ripped corners etc...then the price goes on up there...I personnally would gladly pay $400 - $600 for a mint clean sparkle rig...I wouldn't care if the amp even turned on cause I can totally rebuild one for about $60.
Speakers obviously drive the price up...the CTS are good speakers..and i like them a lot...but the Altecs and the JBLs are the cream.
anyway..on your rig...if its clean...yeah $400 is very fair for a 3x15 sparkle...if its ragged...that's probably top dollar.
The biggest problem is that shipping can kill a deal on these so the only time I've bought the big uns has been when I could pick em up directly. That may be where your buyers are trying to get the price point. i may be getting in trouble with potential shoppers..but if you were to ask me if $400 is fair...it is to me...then just plan a fun road trip where ya'll meet half way and enjoy the visit with fellow kustom nuts.