new and used sacds

i am wondering if anyone has a good recommendation for locating new or used sacds, jazz and rock, at fair pricing. I do use ebay, audiogon, acoustic sounds, music direct etc, but typically they are high priced and dont always have what i look for. i can do plain sacd, hybrid, or multi channel (which will mix down to two channel) My guess is there are local stores or owners that are selling, but living in boston i have not had much luck with the likely suspects. thanks
Amazon is very powerful because not only do they sell their own stuff, small, local stores can join amazon and sell, as well using Amazon's system to reach sellers. I could try to explain it, but if you check their web site out, you will see what I mean.
Try searching