Terry,
Why does this have to be in one SQL statement? It seems to me that you would be better off segmenting each part of the query into seperate SQL's and then use a program to set relations and produce a summation report.
Not only would it be easier to follow a year from now, but if any changes to 'assumptions' need to be made it would be much easier to do so.

It would also be much less of a headache to develop :)