The top shelf stuff at REI will be just as expensive as the top sailing brands. I've never sailed with anyone wearing HPX musto's. They're probably the most expensive set you can get. Do you drive a Ferrari? Maybe you need to find a Lexus brand of foulies to suit your needs. Or a Chevy, Honda, etc.
For lightweight foulies and mid layers, I'd looking into anything cheap from Target, REI, or any other store.
I'm using HL offshore bibs and jacket. I've been very happy how they preform. I picked them up as "last year's models" for 1/2 of what they were advertised for. I've never met anyone who has spend over $1,000 on foulies. If they're on a boat that requires that kind of investment, there are pro's on board and the owner is picking up the tab. If you want stuff that's better than 90% of others have, the Musto MPX are very popular.
I will tell you offshore you need a good stupid high collar on the jacket. The bibs need to be of solid construction. Zippers are not waterproof, get a jacket that has a double storm flap zipper. The water risistant ones are ok for inshore spray, they have no business on serious ocean gear. The bibs with zippers down the side will leak after the 2nd big wave you take. And we all know, zippers break. On day 2 of a 15 day trip, what are you going to do, tape em back together? You're in the fackin ocean mate. You're going to be cold and wet for the next week and a half.
If you go sailing in a climate controlled bubble of canvas dodgers and biminis and have never spent the night clipped in on the rail eating waves in down right scary condition, please do not comment on how well your $50 jacket is working out in the caribbean. Apples and oranges.
With all due respect I completely disagree with most of what you're saying here. For starters the notion that "for serious ocean work...." to me is just marketing. Marketing to fear.
Fact of the matter is, that unless you're racing on a Volvo boat, planing at 18kts in the roaring 50s, you're going to be much wetter inshore than offshore. Inshore is where you don't have the sea room to run off, so you have to go to weather in that SCA. Inshore is where it's shallow and there is an opposing current creating those tall, short period, confused seas that slap around, cause you to bury your bow and get you wet. So why is "inshore" gear less quality than "offshore" gear?
Cherp nailed it right on the head. What kind of foulies you need are determined by your boat and the type of sailing you do. I've been on the big, scary offshore when it was a milk pond (with swells) and on a boat that wasn't wet. I was wearing shorts and Tevas. Most times I've gotten seriously wet was near-shore either by being somewhere I shouldn't be, or when racing. The wettest I ever got was in a gale in the straits of Juan de Fuca that cracked the hull of my wooden boat and I got wet though a top of the line industrial/offshore Danish PVC fisherman's deck suit. (there was no english anywhere to be found on the labels) All other times I have gotten wet were while racing.
My boat, for example, has a clipper bow with lots of overhang and tonnes of flare. I pay for it in unusable length, and in moorage but she is an EXTREMELY dry boat. If my boat and an IOR boat were in the same waters at the same time, you'd need better foulies on the IOR boat. Add in racing and being on the foredeck rounding the windward mark, and you'll need better foulies than you'd ever need offshore.
I also disagree that the top of the line REI, motorcyle, or snowmobile gear costs the same as the top sailing gear. You want gore-tex in sailing gear, look at the Musto MPX that was mentioned. $600 for the jacket, and $600 for the bibs. I've also seen "ocean" jackets for sale for $1,000 (Henry Lloyd I think). That snow-mobiling bib I posted was HALF as expensive and DOES have waterproof, full length leg zips, knee pads etc. Waterproof zips are an expensive feature and are much better than storm flaps. (BTW the quickest way to dump heat after grinding a winch is to zip the side leg zips down to the knees for a few minutes.)
REI mountaineering, backcountry skiing, and motorcylce jackets have stupid-high collars and have every bit as much and more engineering designed into them to keep the wind, rain, snow, and cold out. Who do you think is relying on his gear more to keep him alive: the ocean racer than can go below and change clothes and warm up some soup, or the mountaineer ice climbing above 8 hours above the paltry comforts his tent, let along real safety? That same gear is available to us, for half the price of "offshore rated" sailing gear.
Do most people need even $300 Gore-Tex bibs or jacket? Probably not. Like Cherp said, look at your boat, your bow shape, cockpit design, if you have a dodger or not and mostly look at the sailing you do. If you have an IOR boat, and or like to race, it's going to be wet and you're going to be sweating, so you might as well buy the good stuff. If you have a Hans Christian with a dodger, don't race, lines are led aft, and prefer to go downwind, you won't need the "Offshore rated" stuff, even if you plan to go around the globe twice. "offshore rated", like 1/2 the safety gear out there, is just another way to extract money from those who fear going offshore more than they should.