Need help in getting your digital camera to properly photograph certified coins? I certainly do!

I have tried many different combinations of setup and have yet to find a reliable combination of light(s) and/or lenses to get a decent photo. The plastic case reflects too much light and the coins always come out too dark or have really bad contrast. I also have a lot of trouble with color balance and field-of-view because the coins are sunken inside the white NGC insert.

I am using a Canon EOS 10D with a 50mm macro lens and I also have a ringlight which works great for non-reflective surfaces but not for certified coins.

I have tried scanning the coins without any luck due to the focus problem with the slabbed coins being so far away from the scanner glass.

If anyone has any suggestions on how to photograph NGC coins without spending a fortune on special photo copy equipment please let me know. Any and all help will be greatly appreciated.