http://www.tccsecure.com/csd4100.htm - no price
Great, no price and uses the world-famous DACE algorithm from Bell Labs. Next!
One unit is a "scrambler" which boasts "52,488 code combinations!" The other uses "rolling code scrambling", which I assume is not digital. Next!
http://shop.store.yahoo.com/spytechagency/telscram.html - $260
It's another "scrambler" which doesn't list the algorithm and boasts "thousands of key combinations." I suspect that it is an analog scrambler, not a true encryptor. Next!
http://www.tscm.com/stu.html - several models, over US$5000
Right, the Secure Telephone Units use solid security design and good algorithms. They are expensive. STUs can be used for classified information and they can be bought TEMPEST-spec. I assume that either these things are restricted to government contractors only, or if they are available to anyone with a credit card, they come with a backdoor. So, I checked all the URLs you gave me, and none of them, except the STU, use real encryption, and the STUs are either not available, or they are backdoored. Starium is competing with STUs. Not only does Starium have a catchier name, but they are a fifth of the price of a STU, they are cooler looking, and one could argue that they are less likely to have a backdoor.
And others in the over-US$1000 range.
Right, so Starium is price-competitive, easier to use, and possibly more secure. Oh, and they will sell to anyone who has money, unlike the STU sellers, I assume. I think their initial market are customers such as law enforcement, criminal defense lawyers, and executives who might compare this with a STU, and for whom $1000 vs $100 is no big deal. Government and law enforcement will think it's cheap compared to STUs. It's not approved for classified data (AFAIK) but that might not be a problem for law enforcement work.