Why do Mac & Linux users pay more for things?

I just purchased The Humble eBook Bundle. I primarily use a Mac OSX based laptop (my MacBook Pro), and secondarily use Linux in various flavours (a Lenovo ThinkPad runs Ubuntu, various boxes run a combination of that and Fedora & CentOS, and virtual machines are growing).

It seems not only with regards to Orbitz showing better, more expensive, hotels to Mac users, even when it comes to the Humble Bundle, Mac and Linux users pay more. Are we just conditioned to pay more than Microsoft Windows users?

I’m glad to support DRM-free e-books & great content. Who knows, I might discover something new.