The chocolate giant recently released a limited number of Cadbury Caramilk bars, which flew off the shelves and onto eBay. One listing is asking a starting price of $150 for seven blocks.
"Forget Bitcoin, Caramilk is proving to be a wise investment," one fan said on social media said of the eBay listing.
The white chocolate and caramel bar is made in Dunedin, New Zealand, and was last on regular sale 20 years ago. However, it reappeared in New Zealand last year, selling out in three weeks.
Cadbury spokesman Paul Chatfield told the publication it's all a matter of supply and demand.
“When Cadbury Caramilk was brought back for a limited time in New Zealand last year, we saw Kiwis selling blocks online to Australian buyers for over $30 a block.
“Given the demand from Aussie consumers, we’ve now brought a limited quantity to Australian retailers and feedback from the first stores to have the block on shelf is that they’re disappearing fast.”