why? they're buying from ODS who has been producing high quality regs for a very long time...
Scubapro make most of their own, though some are produced by TUSA. Halcyon buys from Scubapro
Apeks/Aqualung still make their own.
Atomic are a bunch of pissed off former Scubapro engineers so they're making in the US and you're going to pay for it. Zeagles are made by Atomic now
Poseidon still make their own
Dive Rite, Hollis, Hog, and Deep6 all buy from the same mfg, and the reality is that cnc machined hunks of brass are cnc machined hunks of brass, no matter where they come from. I look at it this way. For $360 I can buy a Dive Rite XT which is a sealed diaphragm with a swivel, with reversible second stages. The only other one out there that can say that is Apeks XTX50 with DST which is $600. If the Dive Rite lasts half as long as the Apeks, I'm doing OK, but they'll actually last about the same amount of time. Apeks has free parts for life, as long as you service them every year. So $50/year. The Dive Rites can easily go 2 years and the warranty and all that isn't predicated on service intervals, so you spend $40 for parts, plus $50 in repair bill every other year, and you are $5 ahead per year over the Apeks, or you can service it yourself every year and be $10 ahead of the Apeks per year. Say you keep it for 10 years, it isn't a huge amount of money, but you are likely going to replace regs after 10 years or be out of the sport, so you're multiple hundreds of dollars ahead. This is per "set" so add another $25 to the Apeks for a single regulator set, and another $35 to the Dive Rite total cost, so you're at $150/2years for Apeks, and $125/2years for Dive Rite. Dive Rite has been around almost as long as Apeks, they're mid70's vs Dive Rite at 1984, so they have history, and you're doing quite well with them.
Deep6 is the same boat, though we don't have pricing or anything out for them yet, but their regs are super slick and will be priced quite attractively....
granted I buy basically all of my regs used, and the last set I bought was 3 second stages and 2 firsts and two SPG's from Poseidon Jetstreams for $300, so there's that