I would like ot think we are not getting snowed on this one, but I would love other opinions.

We are having an addition put onto our home. The foundation is poured concrete. Last week when going over the "overages" with the builder, I noticed a cost for covering the slab with plywood. this was not a small cost. I would have thought that that cost would have been included in the base cost of the house. He said, that a slab is unusual and because we want to put hardwood on part of it we needed the plywood. He said that if we were just doing carpet, it would be installed directly on the concrete. I think it odd that this is considered an extra. It is not like he is building us a garage. I feel like it is more like having to buy a car, only to be told the seats don't come with it. If I am wrong, I will put my tail between my laegs and go away. If anyone thinks we are getting snowed, how should I handle the builder? Thanks.

???