Thought I'd chip in as, after nine years on the SBI! platform (BB2 - actually I started with BB1..!) I am finally migrating to WP with the SBIforWP plugin, for similar reasons to you, I think. However, depending on your e-commerce requirements, it may not be necessary.
There are many, many highly successful "pure" SBI! sites out there and indeed SBI! owners have a much higher success rate than most other platforms. The monetisation models they use are suitable for the "Solo Build It!" model, which, much like the Apple Mac, does a few core things very well (and have fantastic support and an incredible community) so solopreneurs can focus on what they do best, which is usually creating great content.
If you are looking to sell individual items, promoted, say, via reviews and other pre-selling pages, SBI! BB2 is fine. I see from your site that this is basically what you have at present. What I have written next I wrote before I looked at it (doh!) so while it is hopefully useful information, it may not be necessary for you.
WordPress allows a much greater range of possibilities and opportunities to sell anything in a way which is much easier for the customer, without leaving the site (as you have to with third party cart systems). This does have implications, of course - you need to sort out security (though a good WP host will sort that for you), make the payment gateway work with the e-commerce plugin and, if you're thorough, integrate the process with other systems like your email list. For a beginner this can be intimidating but if you have a bit of time to figure it out, there is plenty of help out there and the good hosting companies will do most of it for you or advise well.
I personally use **removed by admin, promotion / affiliate links are NOT permitted, please read forum guidelines"
or check out this forum for more options: viewforum.php?f=138 and this page in the SBIforWP action guide: https://sbiforwp.sitesell.com/module-3/ ... y-hosting/]
With my forthcoming WP site, which uses a magazine style theme, I have a membership plugin which allows me to take subscriptions as well as setting up a members area. This way I can charge for premium content as well as downloadable courses. The latter I will, in fact move, in due course to a dedicated online learning site, also using WordPress and course management software.
This requires additional investment in reliable tools that play well together, but I use **removed, not enough posts to recommend products** (not an affiliate link) which provides all I need for amongst other things:
· newsletters and/or mailing list integration (esp MailChimp, very easy to use)
· social media integration/comments
· Google analytics
and a long etc.
In your case, a way of expanding your site might be to build an online community around your niche, though you may be perfectly happy with the comments plugin (and/or to use C2 contributions for reviews).
Really, unless you have the time and energy to invest in taking the site to another level in terms of design and functionality, the advantages of moving to WP may not outweigh the advantages of having a system with which you are familiar and presumably works reasonably well for you. Given you have a physical store, time may be an issue.
Hope that helps - any specific questions you have, do let me know!