I checked several LDS I have driven to and the Apeks xtx50 DS4 DIN is $550 in my area. Another shop has the Atomic M1 for $576. This pricing may be due to the fact that I know him. I haven't gotten a Scubapro price yet.
For the two regs I have priced so far in my area, would I be better off paying $26 dollars more to get the Atomic? I wish the DS4 was a bit cheaper. I've hear the Atomic is really high, so my Apeks pricing is probably on the high side. I'll throw the SP in the mix when I get a price.
And now I have a quote from my ScubaPro Dealer. The MK25/S600 is $579.70
On the plus side, they only charge a $20 service fee for 2 second stage set and all parts are free.
Service on the Atomic M1 set would be $100 every 2 years.
It seems that regulators are like car brands. Everyone has a favorite brand and I will eventually just have to pick.