IMO - I don't think your dealer is really doing you any favors with that bid... The setup charges are "over-the-top"! He's charging you twice to setup the mower!
You could do better with a dealer that's willing to ship the tractor to you -- from 3-400 miles away!
Lastly; are you confident that a 2305 is enough tractor for 46 acres and a home, etc. (If you could rent out or sell about 40 of that; you'd likely manage things a whole lot better!)
Will you be planting trees, cutting the old ones out and digging stumps, etc.? How much mowing will there be on those 44 acres? It will take some time with a 54" MMM... How much of that will be "rough" mowing? That mid-mount will really struggle (or not work at all) if the grass is mixed with shrubs or really heavy brush.
With the current economy - there's no need to get in a rush to buy - 'cause there's some good deals out there if you're patient.
Good luck.
AKfish