If you can buy the OS separately (and it is not a hoax) it kind of makes sense from TX's point of view. This way, they sell you their expertise with their own CFW, which at this time is far more advanced than everything else and the tools on top. Or you can buy/build your own and still use their os. So this means that with the current pricing as we know (which might be wrong of course) they sell you the tools for $10-15 which is a great price and their software (which is where they put most of their working hours) for the additional money up to $25-30. Can't see a fault with that. Generally speaking, when buying something you pay for somebody's time, be it a service, software or hardware. If the free CFWs by the time the TX one come out are much worse then i see no reason for people not to buy it.
This shuts up all of the people who think TX is overpricing stuff, as in this case they are not selling cheap harware with a markup but rather their hard work.