In the local TSC, they have their (MTD built) Huskee line of "Garden Tractors". They had a (last years model) 25HP, 50" cut for $1799, or the new for this year, 25HP, 54" cut for $2799!
Yep, a cool grand for 4" more cutting width. On your budget, you might look also at Husqvarna. I have one of their larger mowers (25HP Kohler, HST and 50" deck), and its been trouble free and does a nice job.
I live on 5+ acres and keep about 4 of that manicured, the other acre is under water (my pond). I can mow my whole place in less than 5 hours with the Husqvarna. Not fast, but not bad for the price.