They really aren't worth much more than $150
They are worth precisely what someone is willing to pay for them, today.
It is really starting to get pathetic to see people on this forum whining about prices going up, especially when single skull-shaped keycaps are selling for hundreds of dollars.
Supply and demand. When supply is fixed and demand rises, prices rise at least as fast.
End of story.
If you want low prices, build a time machine.