www.deepdiscount.com has done Amazon one better. The Chan sets are marked down to Amazon levels plus if one uses the coupon code SUPERSALE at checkout an additional 20% discount is applied. This knocks the Vol 1/2 sets down to about $24 and the Chanthology down to about $29.
Some on here have asked about Mike Shayne lately, the price of that set will be about $18 with the discount.