The proposed amount covers a functional CMS developed under Django/Python Framework.
I arrived with this amount as your post claims that tasks mainly focus on template rendering, which is indeed
"We're talking about a fairly simple corporate website.
I expect to implement 10 different page templates."
The proposed amount suggests 100 euros for each template, further development cost are for tests and Django specific renditions.
Before awarding this project, I inquire for an agreement to be settled first. I understand that we are using Django's default features, wherein, to implement other features designed for your website shall be covered under another agreement/project.