And here is my answer to your second question (first number calculated based on list prices, second number based on actual amount paid because items were used or discounted; numbers are not corrected for inflation ;) ):
cd player: 8% (13%)
pre amp: 5% (9%)
power amp: 7% (12%)
phono pre: 3% (4%)
turntable: 6% (3%)
cartridge: 1% (1%)
stands: 3% (5%)
speakers: 21% (23%)
speaker wires: 14% (6%)
nf cables: 20% (11%)
power cords: 12% (14%)
cd player: 8% (13%)
pre amp: 5% (9%)
power amp: 7% (12%)
phono pre: 3% (4%)
turntable: 6% (3%)
cartridge: 1% (1%)
stands: 3% (5%)
speakers: 21% (23%)
speaker wires: 14% (6%)
nf cables: 20% (11%)
power cords: 12% (14%)