The Xcal III is worth about $400 with basic tuning. So $500 is OK for supercharger, dyno should be more. Normally at least $300 to do 3 pulls without software changes, so $800 not bad. Woodbine did my last tune, since he drag races L's he has real world dyno experience. Dyno is nice, but not required. MAD should have some references.
http://www.woodbinemotorsports.com/