It's Aquatic Collection in Hayward. Their prices are pretty decent: small Philippine Regal $45, small Indian Ocean Regals $120, Red Sea Regals $150-$180. I got the last actually at a good discount (I bought almost half the regals they got lately

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According to them they see really no significant difference in appearance between Red Sea and Indian Ocean Regals. The biggest difference seems to be the acceptance of food - in their experience the Red Sea eat better right out of the bag - I can't confirm that as I didn't have any eating issues with the Indian Ocean specimen and the only Red Sea regal I ever had (from DD no less) never took a bite.
The issue with Red Sea supplies these days is that the only country that collects and exports them is Sudan (at least that's the info I got). Egypt and Jemen stopped their exports (political unrest, civil war).
The issue with Sudan is that it can't directly ship to the US (rouge )nation status) so all their shipments into the US go over relay hubs (Sri Lanka) or European wholesalers. That adds to the transport time (and cost)
As for the color difference - I feel in pictures Red Sea specimen have a more solid orange tail fin while Indian Ocean specimen are more yellowish with a hint towards green in their tail fin.
Though side-by-side in the same tank I couldn't see a difference at all.
Pacific regals have besides the grey-blue chest a more greenish tail fin and are overall more bluish-gray.
I feel this actually goes beyond a simple color difference. I'm coming more and more to the conclusion that the Indian Ocean (of which the Red Sea is a subset) and Pacific Regals are actually two distinct species. There is a clear separation line and no area of overlap I would know of. Also the behavior of yellow and grey-blue regals is quite a bit different.