Right, many more (relatively) economical options with an over/under design. Beth Stacks would be attractive to me because Bethlehem seems to design all their stuff to be compatible with concentrators (20 psi for the bigger ones).
https://www.mountainglass.com/The-ST...rner-Bethlehem
Edit: I forgot about the GTT Scorpion, it's a true two-stage for less than $700. (The triple-mix models get all the love.)
https://www.mountainglass.com/GTT-Scorpion-4-Stud-Torch