Free:
You can extract posts in RSS format. Add "posts=99999" param to URL to extract all posts from a blog.

www.blog.com/index.php?tempskin=_atom&posts=99999

Paid:
- [url=http://forums.b2evolution.net/viewtopic.php?t=18175]Feed importer plugin[/url] can export complete posts in XML, CSV and JSON formats.
- There's also a [url=http://b2evo.sonorth.com/show.php/bimp-importer-migrate-b2evolution-to-wordpress]b2evo to wordpress importer[/url] which can import posts, categories, comments and media files directly in existing wordpress blog

That'll work, thanks. ^_^