Completely misleading title: "sets record low price" indicates that it has done something, but the article says it has not been built. This, it has not set any price. Someone has projected a price.
The price is the highest the energy will cost, for the lifetime of the contract absent force majure.
Why would the owner sign? The contract gives certainty. The contract means the owner can now get funding, they have a guaranteed income stream across the life of the contract.
reneweconomy's self-description.
"Australia's best informed and most read web-site focusing on clean energy news and analysis, as well as climate policy."
It's an advocacy organization probably funded by clean energy lobby. There are quite a few of these climate advocacy "news" organizations being spammed on social media along with their supporters in the comment threads.