Any chance previous returning customers might score a price break with this ball? 
This is the single most difficult situation that comes about from improving a product. I would love to swap them all out, but it's just not feasible to do it.
But I certainly understand, and feel the same way when I buy something that goes obsolete. So here's what I can offer;
Anyone in the US who has purchased an Electric ICE-T Trackball, or Electric ICE Trackball upgrade kit, can buy one of these new balls for $17
shipped. Non-US customers will need to have the shipping costs calculated. I wish I could do better, but I'm afraid that is the best I can offer in this situation. As a point of reference, HAPP lists their translucent 3" replacements at around $36 each and clear at $60,
plus shipping. Neither can hold a candle to this one for lighting / color changing purposes.
For anyone else, the upgrade kits will still be available and I had both 3" and 2.25" versions manufactured. A single color version using the NovaGem light source is coming at a lower cost than the RGB version, and I will consider making only the ball available as well, albeit with a premium attached.
RandyT