Without additional information, it's hard to provide any input as far as what you should expect.
The first question I would be asking is "what impact does this product launch have on the community?" PR is about the specific area you are targeting, as opposed to general marketing which can cover much larger geographic areas. Is this product made in your local area? Does it echo some value of the community? Or is it something that meets a specific need of the community? All of these aspects can lead to higher conversion rates for those within the area, which you can then quantify against the cost.
As far as cost, I'm again going to have to say that there isn't enough information provided. In some cases, PR can be free. Just providing the story to local journalists can be a decent start. In other cases, you're paying membership fees for the local chamber of commerce, etc.
Sorry I can't give you more detailed information without knowing more about your product and community. Feel free to reach out for a follow up call.