QUOTE
Operating Rules for the NYCE network. They have a rule which states "Merchants shall not establish minimum or maximum transaction amounts except as outlined in the cash back policy". Reading the cash back policy indicates the only restriction there is not to set a maximum amount less than $50.
Dont know if this applies to Pulse, star or any other pin network.
I also found out if I read it correctly Maestro and Visa interlink has the same rule.
One added note, the maximum is subject to your debit card pin daily transaction limit.