The Hustler FasTrack Super Duty has 3100 hydro's, the same as the Gravely XL HD,
http://www.hydro-gear.com/Main/oem/hustler.
The local dealer by me gave me a price of $6,400 for a FasTrack 54" verses a 52" Gravely XL HD for $4,800, that's a $1,600 premium or 133% more.