There have been several new issues lately that have been posted for sale on TCB.

What I see is:
$1 chips for sale at $2-2.50 over face
$5 chips for sale at $3-4 over face
$25 chips for sale at $6-10 over face

Why is there a difference in dollar markup? Especially for the $25 chips?

While I understand that the higher the denomination, the more it costs to buy inventory but that cost is not significant. And shipping cost is the same.

Shouldn't the cost of chips be more in line with availability, which is unlimited for these new issues of house chips?