Bluehost Sitelock price per year is $23.88 while the regular price is $99.95 per year. The SiteLock can be purchased when one is buying hosting services.
SiteLock is a feature within Bluehost that offers high level security by preventing malware and virus attacks. The attacks could otherwise crash your site, hence making it even more expensive to remove them from your site.

When paying for hosting, you are given an option of deciding whether you need SiteLock or not. If you really care about security of your blog, it’s good you select SiteLock.It’s better to pay $23.88 per year on SiteLock than to spend $100 once for malware/virus removal.
The $23.88 is 80% less than the normal price of SiteLock.
When a site is secure,it will rank high or search engines.SiteLock and SSL certificate are two important things a website should have.
If you are planning to join Bluehost,check their pricing here