If your minimum pricing rule won't allow you to compete with the lowest seller on Amazon there are two ways it can price and this is dependant on a Setting called 'Best Price' in the Amazon Settings Screen.
If Best Price is set to Yes you will price against the first seller above your minimum price.
If Best Price is set to No you will list at your minimum price.
NB. If you can't compete with any sellers you will be priced at your minimum.
To change this setting go to Settings / Amazon Settings / Price Check Settings.