One of the bigger concerns I have aside from design is the fabric(s). I haven't liked the fabric choices (in both durability and look in some cases if not one or the other) in many of the "national" sweaters. I know a bunch are made by Nike but the fabrics shown in previews so far haven't placated me, and the Reebok ones are still pretty nice. I'm not a fan of extra-light material for hockey jerseys, they absolutely should have a little heft to them. Definitely one more reason to pick up the Reebok retro (other than the fact that we aren't going to see a third jersey at all next season and in no way are we going to be guaranteed a retro third again in Adidas branding.)
Has anyone come across a shop selling retros for any cheaper than FanAttic?
No idea. You can try Jersey City. IIRC there's also a… shadier merchant who sells sports memorabilia in Marlborough Mall but I have a hunch a lot of them aren't legit - if you don't care and want to pay $50 or less they may have something retro-ish?
I tend to buy the authentics because there's actually a lifetime repair guarantee on them. Had a home jersey fall apart on me (the cresting was falling off) and I brought it to FanAttic and they sent it away for repair for like 15 bucks. Got it back in great condition with all the autographs unaffected - and every patch/numbers (not just the Flaming C) was stitched so it wouldn't happen again. And again, at 70 bucks a sweater it's a damn good deal right now.