There are many legitimate dealers of STAM selling online or at least have some sort of online presence. Most are US or Israel based businesses that have expanded to the Internet sometime in the last 20 years to reach a wider audience. I don’t typically spend more time on this site other than to check out the news a few times a week. I saw the thread on tefillin and posted. I am an educator as much as a dealer of STAM and felt I had what to offer to this discussion and I’m glad it has been enlightening.
I recommend going to page 2 of kashrus Korner of this site to read 4 helpful articles that I was invited to write a few months ago.