I recently replaced the hydraulic pump on another brand of tractor, come to find out, even the housing had worn out. The seal had given way and filled the crankcase with hydraulic fluid. Anyhow, the dealer was big bucks as you mentioned, but I went to a hydraulics repair place and they got me the same pump for several hundred less. It may be that pump is a common pump for other applications and is available elsewhere.... just a thought. Good luck with it.
                  Cal