With shipping (and a velvet dice bag) 20 custom dice cost me around $30. Not too bad. I played a practice 2500pt Ard Boyz game with my friend Kung Fu Dave and his Tyranids and they served me well. They didn't roll like weighted dice or anything but they didn't come up all ones either ;).
Some details about the dice. They are "bigger" dice or about 16mm each, not huge but not the small dice that Chessex sells in their "dice blocks" you see at most stores. It was basically about $1 each for the dice. As I stated above, Chessex doesn't have a shopping cart system of any sort so I had to email them through their order email on their site. Here is a link to the custom dice page:
I got a prompt response from Joseph Kogin. I requested what options I had for for red dice and here is what he responded with:
"Currently, I have the following "Red" dice available with the "6" face customizable: Opaque Red/white Signature Gemini Blue-Red/White Signature Gemini Purple-Red/gold Signature Scarab Scarlet/gold Signature Velvet Black/red Signature Vortex Burgundy/gold Most of these colors are only partially red or have red print on them as in the case of the Velvet Black/red color. The color after the "/" is the color of the print on the non-custom faces of the dice. I can accept most standard formats and can definitely use .AI, PSD or .PDF format files if you want to leave your art in its native format. Images that can be rendered in a one-color format (2 bit) would be best for this process. There is not need for your to scale the image to size. Full resolution images will generally make for better engravings. If you send pixel art as opposed to vectored images, please send it in a relatively high resolution. 300 DPI would be great, though simpler designs can be rendered at lower resolutions."
I used Adobe Illustrator to trace a scan of the Blood Angels symbol from a Space Marine decal sheet. If you make your own make sure its one color and try not to make lines that are too thin, they may not show up too well when its cut out of the dice face. Here is a 300dpi jpeg of that Blood Angels symbol for anyone who wants to use it to make their own dice (click on image to download the print quality version):