Hi, look on the "Master merchant" add-on, or find a special trading guild for that things..
Its useful if you use "link in chat" feature And write "MM pls"
If you are on PC/NA, I'm getting 15-20k for most blue furniture designs. For green I'm selling between 1250-3500 depending.
Purple ones I'm selling for 40k and up.
But, the prices should start dropping quickly soon.