According to their website Gretsch still has two versions (regular and vintage) of Champagne Sparkle available on new USA Customs. Just because Precision, etc. may chose not to stock it doesn't mean Delmar isn't making it. Also the copper sparkle on Gretsch's Catalina jazz sets is similar to Champagne.
Bermuda sand wasn't a particularly good match to original Champagne but was all that was readily available for many years.
It's possible that these two wraps that Gretsch is using are exclusive to them which would mean that the wrap sellers couldn't get it to sell.
For the price to shoot up on vintage drums requires that demand exceed supply. I'm not sure demand for this color is climbing that steeply, regardless of whether or not new (or rewrapped) drums in that color are available.
Just my 2 cents.