10% discount is the usual "give back" by the dealer. 15% is pretty good, maybe 20-30% on accessories and cables.
Uru975, 30% discount on speakers??? Were these dealer demos, a discontinued model, or did the dealer stop carrying the brand? A 30% discount on new speakers sounds pretty steep!
This applies to "bricks and mortar" stores...online vendors might give better discounts because of their lower overhead.