First off, Welcome to the FlowerChat Community....
Regarding your question, I doubt you'll get anyone to reply with an actual cost that they paid for their sites. I know that while I have sites available for sale I will not post the costs here preffering to deal with each florist in private.
The costs associated with wire service sites are available on their company website's generally.
Perhaps if you posted the link to your directory you may get some more replies, a Google search this morning did not turn up your *directory*...