WordPress blogs are complex pieces of software with a threat surface that expands with each plug-in or theme you install. Whenever I set up a new WordPress site, one of the first things I install is Wordfence - a security plug-in that provides a number of services that help me monitor and manage those sites. Wordfence has launched a WordPress Security Audit service.
The US$149 price-tag gives you access to an experienced security analysts who performs a 59-point inspection. The output is a report that includes detailed recommendations for improving your site security. It also includes a Wordfence Premium license for your site.
With a single Wordfence license costing US$99, the extra $50 looks like good value. The service is backed by a 90-day guarantee and Wordfence will clean your site free of charge should it get hacked within 90 days after the audit.
A sample report [PDF] is available.