I find there is a great market in the sub $1k range. But it's like cars. Some folks got to show off, some folks not so much.
Some of it is blatant rip off in my opinion. Generally speaking, you have 2 peices of wood, only one join, some steel wire, and a few bits of electronics. I have trouble getting to $4k from there.
Take a 4 x 12 cab for instance. Koch sells one for $1700. Nothing special in it, it's just a box with 4 speakers. I build some of my own cabs and guitars, and from one $70 dollar sheet of 3/4 inch birch I was able to cut a complete 2 x 12 cab in standard dimensions and a 1 x 12 sized as the Traynor version to fit the Darkhorse amp.
Realizing I still have to add speakers, tolex and grill cloth, I still have a problem getting from $70 to $1700. But some people will "need" that $1700 cab. I guess I would have to call those folks "singularly motivated".
...so ever since then, I always hang on to the buckle.