I think this is a good idea. VaultPress is an awesome product, but doesn't seem to be as popular as it should be.

I'd love to actually use VaultPress myself, but I find the price is too high for my liking. The US$55/year deal is no good as it stops at 30 days of backups, which means tough bikkies if you don't notice your site got hacked within that 30 day time period. Then it's up to US$165, which is almost as much I spend on hosting. So instead, I back everything up to Amazon S3 which costs me almost nothing (apart from the considerable setup time). If I were hosting anything more than my own blogs (and a few other non-profit sites), then I'd almost definitely sign up for VaultPress though.