RRP was $50, and they do price it that way for the new design.
It is listed in many places as $10+delivery. But in Amazon, i ordered 3 of them 2 weeks back then and didn't get charged with delivery. I wasn't on Prime.
It was a slight gamble as i couldn't find any reviews on this product, unlike Thermos.
We tried them with the kids and they loved it. I don't know the quality of thermos equivalent, but this is big and warm enough for primary kids lunch.
Other variants are more expensive ($15):
https://www.amazon.com.au/dp/B084H6WPKD/
Updates
Confirmed with others that it is minimum 3 for free delivery.
Not a prime item, charging $7.95 del