That is nice website, and quite a different time estimate. I know that the track hoe that I am planning to use has bigger bucket, and number of trucks and distance has a lot to do with that.

here is an interesting site - fillexchange. Even splitting the cost would be great.
http://network.acen.com/xchange/fill/

How does your weather station work? I see the cell phone - can you get real time data and download historical data?