I don't know about that regulator personally, but I think you could get a better regulator for that kind of money, or even less. You can buy a cheap regulator like the one from Aquatek and then buy a post body kit from a member such as BettaTail. I have bought multiple units from him. The post body kit is the solenoid, needle valve combination that will just screw on to the regulator. You need a wrench to switch them out, but I did it successfully my first time.
Also, I bought the Reef Fanatic regulator/solenoid combo from Aqua Cave for $150 and that thing has been working awesome. If I get some more time I'll research some more ideas and perhaps your potential product in particular.