It appears to me that what you have been offered, and I am just guessing that you had Best Available selected since it is the default, is an "A" seat (first) going in standard and a "W" seat (economy) returning standard award level.
The best economy itineary was a rule buster and why do a rule buster in coach for more than a seat in first.
After the deductions for online booking it came out to 32000 although my calculations seem to think that it should have been 32.5k. But what do I know other than a lot of folks are going to not understand any more than we what we are doing.