Google is getting VERY good at catching spun content so you'd better be talented at manual spins. If they DO catch you, of course they'll spank you... and hard. So anything you use spun content on is inherently AT RISK. Worse yet... Google gets better at finding spun/poor content every year. So in the longrun you're screwed. I'd weight your other options and see if you couldn't find a cheaper source for manually hand written content.
For a blogger who has to publish multiple blogs on daily basis, it is tough for them to write unique content, especially when writing on same topics. In that case, spin bot tool could be used to avoid self-plagiarism and to maintain the quality on blog posts. As spinbot change synonym automatically but you can pick the most relevant synonym using out tool.