The Australian demand for the limited edition, New Zealand-only, run of Caramilk is leading to Kiwis creaming it on eBay.
A pack of five blocks with free postage was on sale for a whopping A$149 (NZ$159). One block of the Cadbury classic sold for A$40 today.
Originally created in 1994, the white chocolate-caramel blend hasn't been on shelves in over a decade.
James Kane, country head of Mondelez which owns Cadbury, said the company had worked hard to bring back the flavour after strong public calls for it.
"People who remember Caramilk will know it tastes like nothing else on the market today and will take them back to the 1990s, sparking fond memories of sharing Caramilk with family and friends," Kane said.
"Those that have never tried Caramilk before are in for a real treat."
A Facebook page "Keep Cadbury Caramilk", set up in 2012, was celebrating this month, with fans quick to take to the page to express their excitement.
"After years of begging Cadbury to bring it back, we finally have success," the page said.
Cadbury staggered the roll-out of the flavour from distribution centres into stores last week and said it would be widely available from today.
"We know Caramilk has a flavour all its own, and we're confident it lives up to the promise of the original that Kiwis loved all those years ago," Kane said.
The Caramilk was made by cooking milk and sugar together and then blended with cocoa butter.
It was then refined and churned before being moulded into Caramilk blocks.