My Sherwood Magnum alone was around $370 at my LDS. That wasn't including an octo or console.
It handles well in Monterey waters (52F / 11C). I'm not sure how capable it is for colder waters however.
The manual says it has passed "EN250:1993 for regulators used below 10C (operating at 4C)"
It uses a closed piston first stage. To equalize it leaks air from an equalization port, not enough to affect your SAC, but enough of a constant tiny stream to get your buddy to notice.
After dives your first stage will still equalize, even after changing tanks, so sometimes it may be hard to tell if your O-ring is leaking or if it's just the equalization port. I find that putting your thumb over the equalization port stops the hissing so you can tell which leak is which.
The Magnum regulator package (first and second stages) should ship with 2 exhaust tees (a small and a wide). So if you don't get them then you're missing out.