[molsongolden]

b) is the most likely situation here

The 2x calculation is similar in the US. I've also seen "3x your hourly rate as an employee" if you're relying on the contracting income. It's important to account for the time you'll spend doing sales and misc. non-billable business building.

There are lowball contracting offers all over the internet and people sometimes accept these for various reasons. A higher tier of sustainable contracting does exist though, with most of the higher paying work sourced via networking, not via job boards.