This site is great. Two things to think about:
(1) I'm 99.9999% sure Patrick McKenzie will be here within the next 15 minutes to tell you in detail how to pull this off, but you are selling something that has a natural content SEO fit and you should chase that down.
What you want to think about are ways to break down your subject matter into categories (again: it's natural here; the Joyful Mysteries, the Sorrowful Mysteries, etc). Look for other angles; when are people praying the rosary? For what occassions? Think about kids, think about class projects, etc. Break content into atoms.
For each atom of content, have a system that allows you to host it on its own page with a meaningful URL, a meaningful title, a meaningful article summary (meta description), the atom's worth of content, some contextual content (general stuff about the rosary, how you got to that page, etc), and some basic call-to-action to get people to pivot from reading information about the rosary (which is how you got them to your site) to looking at easily buying a rosary (extra bonus points if there are convenient ways to customize the rosary based on the atom of content the user is looking at).
Note that this sounds suspiciously like programming and application development. Who'd have thunk it; selling things online can be an engineering process!
I have been continuously astonished by how quickly you can capture swaths of Google search space by generating content that directly and succinctly answers one very specific question people ask Google. Remember: do not try to answer every question on one master page. Anathema! Have a crawlable sanely-indexed sanely-browsable system on which you can hang hundreds of pages.
You can start all these things very simple, and once you start, if you attract a baseline level of traffic, you can start A/B testing, which will get you to a place where you can start assigning a dollar value to each thing you do for the site.
(2) This system looks very well set up to address the case where I want to carefully buy one customized rosary. Isn't it very common that people want to buy many rosaries, say for the 60 students in the 5th grade at St. Barnabus elementary, or (if you are one of my aunts) every one of her 18,000 nieces and nephews?