Order of 'Call for price' properties in listings

Hi

My property listings are sorted by price, in ascending order.

When I have a ‘call for price’ property in a listing, it appears randomly in the ascending price listing.

I have 2 questions:
1) Is there anything within the module scripts that assigns a specific place for ‘call for price’ (i.e. prop ties with no price) in the ascending order of prices?
2) Is there a way to force ‘call for price’ properties to be listed at the END of the property listing, so that all ‘call for price’ properties are together (after the properties with prices)

Thank you.