Of course, if you don't know when someone took the course or which agency, you can't really compare the price.
And NO scubaboard member would pay a discount price for a cut rate course. After all, PADI DM requires at least 2 pool sessions with the instructor, 2 days in the pool interning BOW, at least 10 days interning other classes and several class sessions doing the nine knowledge reviews. Plus, at least 2 sessions doing the stamina excersises. My course has required more time than this, but I'm listing the bare minimum.
A 300 dollar course would mean the instructor makes peanuts, at best, and only newbies would pay for cheap instruction.
My course, which is about 1/2 done, cost $625.00 plus books, in the NY/NJ area.