Don't cheap out on your regulator...get the best you can afford.
I purchased a SCUBAPRO Mark V in 1972...at the time it was their top of the line regulator. I'm still using that regulator today...has never failed me. I've used it in the warm waters of the Carribean & Hawaii, the colder water of Monterey Bay Ca, but mostly in the waters off the North Caolina coast. Even used it once ice diving. Never, ever a problem.... It is the only piece of dive equipment I have never had to replace.
Sometimes my regulator embarasses my 22 year old son...it definitely doesn't look like the sleek, low weight gear of today. We were on a dive trip once out to a tanker that had been sunk by a U boat off the coast of NC and he made the snide comment that.. "dad, you've got the oldest equipment on this boat", to which I replied..."son, look around, I'm the oldest diver on this boat!!" Just because something is old doesn't mean it still doesn't do the job properly!!!