Inventory included with property

[Steven LaBoy]

I have a seller that wants to sell his property, 3.3 acres which includes a house with two units, and three structures/barns/garages converted into businesses. He rents out two and converted one into a hardware supply business. He wants to include the hardware supply inventory in the deal, but I am not sure how to assess the inventory or the structures for that matter. I'm only aware on how to assess the actual house on the property. Any advice will be appreciated!