Curio also has a purchase option the same as Tinderbox. Pay once, get updates for a year, use it as long as you like.
I tried to like (and even use) Tinderbox, and have about $500 invested in that, including annual updates, his books, etc. In my use, it’s a kludgy, cantankerous, weird program that works the way Bernstein works, and Bernstein has a very Henry Ford model of software development (any color you want, as long as it’s black). I’m no stranger to programming, having started with machine code (I still recall F8 2D A3 F8 11 A1 to start setting up video on my first machine) and visited such oddities as b.f. (language, if your ears are tender). Still, Tinderbox’s “language” is terrible, as is the way the commands are entered into horizontally scrolling boxes in obscure place.
Other times you just want to change the font ( e.g., e.g., and be sure you actually need whatever you need because money doesn’t grow on trees). Tinderbox makes even changing fonts/colors/etc. exceptionally obtuse.