I think there should be a rating system. BNIB and LBNIB are super subjective.
Keep it simple, 1 to 5... 1 being absolute crap and 5 being Brand new, never carried, never sharpened, no nicks no dings.
1 to 10 is way too subjective, can you really say it's a 7 and not really a 6?
I present to you the DC rating scale (Ha! I took a little too much liberty perhaps)
5: Brand new never used, never carried, no marks, centered blade, zero blade play and perfect lock up. A perfect factory original including factory original EDGE & or accessories (scales, stand offs, ect)
4: A very good - good condition lightly carried blade, used for very light cutting tasks, no marks anywhere, centered blade, zero blade play in x or y axis, sharp with even bevels from factory or otherwise, modded with or by aftermarket parts but can pass for factory (e.g. sharpening, scales, no blunted tips fixed or otherwise)
3: A user in good - fair condition, may have scratches from sharpening, tip may be blunted or may have been re-tipped. Blade may be off center, there is some up and down or side to side (or both) blade play. Scratched pocket clip, noticeable wear on the scales. No stripped screws
2: A user blade in fair to poor condition with scratches and or gouges to scales and or blade steel, noticeable blade play, may be off center, well worn, may have stripped or missing screws. Still a very restorable blade
1: A poor condition blade you would probably leave in your tool box, not restorable.
Of course you can have a brand new never used blade with blade play from the factory but you will have to disclose any and all imperfections.
Or you can have a perfect user. The numbered rating system is a guide not an absolute (and a simple one at that).
With this system, guys who use their blades for a year can't or wont sell them as BNIB just because they think it "looks clean enough" Or they won't be able to hide imperfections with crappy pictures.
Before you sell a blade here, there should be a check list and if it's anything less than perfect..... Please describe the wear or damage in a couple of words... thats it, no biggie.
Blade: Perfect
Edge: Sharp
Bevels: Even
Scales: No wear marks
Hardware: No stripped or marked screws
Clip: No scratches
Centered: yes
Orig box and papers: yes
Feel free to let me know what you think....