Quote Originally Posted by Niwashi View Post
I believe it's the region it's being sold from (and therefore whether there's tax added) that's the third criterion.
Nope.

Its the time, when the retainer got sent back to the market.

The rule is: the last one is the first one.

You can test it. Put something into the mb at the same price like others and wait till you are not on place one anymore. Call your retainer and send him back et voila: you are back on place one.