You didn't mention the engine type. The Kaw 17hp seems a little low on torque, I had a 18hp Kohler twin (20hp is supposed to be the same) and it did fine in most situations on a 48". That would affect price. Yours looks like a Kawi.
Most buyers want size over nimbleness, so the mower's not in big demand except with startups short of cash.
I'm actually in the market for a 44" as a backup and to do props where the 48" might not squeeze in.