...then in the case where a price is set to zero, this message will be printed instead. If the pricezeromessage is not set then products with a zero price will be displayed as Price: $0.00 as usual.
I went to the .asp parameters ( https://www.ecommercetemplates.com/help/ecommplus/parameters.asp ) and use "find" in my browser to search for "zero" and found it pretty quick.