I kept the 445 when I got the 2305. Both machines is great. 445 i a great mower and I use the 2305 for loader, pallet forks, blade etc. Two machines are better than one.
I think that sounds a little high as well. That machine WITH the loader and mower lists for $15,500 new around here. If they are giving you 4 k for your trade in, that math does not compute...