Looking to buy my first drysuit as I live in the Pacific Northwest west and cold water diving is a must.
I'm only a little bit ahead of you in the purchase stream so I'll give you my two cents. First and foremost, dive what you want to buy first. Forget what anyone swears is great and try it in the water, even if its just a pool session. If seeing is believing, then trying is reality. That said, I've found it hard to rent dry suits, so I've tried to try the various styles of suit - trilam, garbage bag, compressed etc, then proceed to hopefully seeing what I want to buy - usually on someone else at the local dive site. By all means, don't be afraid to walk up to someone wearing what you want and ask. I find most folks will give you the time of day if approached in a humble manner.
All that said, DUI (at least up my way) seems to be the high standard by which dry is currently measured. Lots of lovers and but just as many haters. Check out their website and read up in other places, not just here. I've read alot of "had to send it back for adjustments" seems to be the norm. Custom tweaks is an accepted practice for their product - neither good nor bad, just comes with their territory. Once dialed in though, (some) people won't give them up. I'm diving one this weekend to try to understand what all the hub-bub is all about.
I dove a Fusion in the pool as part of my dry spec. I loved it at first bite. But I have no comparison except my 8/7 semi dry which is a monumental struggle with a rubber beast to get on (great in the water tho). I dove a front zip Fusion Sport because I heard front zips are cake to get yourself into. Not so. Or at least, 90% is fine, but the last 10% you can't zip by yourself because its over the shoulder. So for me that eliminated the "must be a front zip suit" (some folks do the bungy thing, and if I have to do that, I can probably just do the same in a back zip - YMMV). Price is for sure great on the Whites. I don't know for sure, but an LDS buddy of mine says markup is well over 100% on the suit. Probably more. Does it matter? Not really. All scuba has wicked high mark up. C'est la vie.
You also want to get a handle on what kind of seals are available for the suit you think you want. Pretty much everyone opts for some kind of zip seal (ie user replaceable) vice welded to the suit at the factory. Not really sure why the factories even bothers to offer the later. Then there are different types of material for seals (neo, silicone, rubber).
Oh yeah, if you like to piss in your wetsuit, you better check into a pee-tube installation. Plenty of YouTube on what they are and styles. I actually learned the most about the niggling details of how this thing works by watching the she-pee videos (careful, not for young eyes, or the sensitive). You can DIY a pee valve on your suit, or have the factory do it. Spend $80, or 380, depends on what you want. Or you can go the zipper route if you can hold your bladder in the water, but not out.
And then there's undergarments, because you're not going to be in the suit naked (defeats the purpose of warmth). Choose your poison on this one - anything goes, but not everything works well. And then there's gloves (dry or not), boots (or not), hoods, different valves or custom valve positions....***sigh***
All in all, with dry, I found the suit part is just the tip of the iceberg (or money pit I suppose). There are a lot of other "items" that will eat at that big pile of cash you think you are starting with....
If you buy something, let the rest of us know how you found it after a few goes. Good Luck!