Incremental/Differential/Versioned Backup for WordPress

We’re searching for a versioned backup solution for WordPress and can’t find anything – not even incremental/differential backup. There are lots of backup plugins that will save a complete copy of everything (database + files) on a schedule – that’s great as far as it goes. But we want to run backups every night incrementally or differentially – so the backup size doesn’t balloon out of control. It would be great if it were versioned, so we could restore a given file or post, but even an incremental/differential backup would be welcome.

Does anyone have experience or ideas for versioned, incremental or differential backups of WordPress sites? Either for the files, the database entries, or both? We don’t mind paying for a plugin that would do this!