This site
http://www.autodetailingsolutions.net has some cheap prices on certain products, such as klasse, wolfgang and certain meguiars products.
If you buy one item, it ends up being about the same price as other sites as they charge a few more dollars for shipping, but you can save if you buy multiple things.
Also autogeek goes by palm beach motoring on Amazon. Certain items and usually shipping is cheaper through amazon.