I believe there are some standards from an organization (ATKI?).
I'd like to see standards posted (as important) at the top of each trade/sale forum.
In the mean time, here is my take on the subject.
--------------------
"New", in my mind, means "never taken out of the box". This means no handling, no opening, never left the plastic since it left the factory. Mint should have much the same meaning.
Like new is a very vague term. I really despise the term LNIB.
I believe that if it was purchased and taken out of the plastic and box, it is no longer new. It is now "used". Even if it was just taken out of the box, and put back in and returned, it is used. It may be in very fine condition, but it is still used. I would liken this to sex: Have sex once, you are no longer a virgin. Just because it has only happened once, you can't go around calling yourself "like-virgin".
Another big problem not currently addressed is the difference in quality between factory knives. Just because a knife is NIB does not mean that it is "perfect" by any means. By purchasing a knife second hand, you place yourself at some risk. Buying a knife from a dealer, you have the option of returning the knife to the dealer for a refund or a new knife. Some warranties require that you be the original owner and have the receipt (Example:
Benchmade). This means that if there is a problem with the knife, you're stuck with it, unless of course you manage to talk the original owner into sending it in, or refunding your money.
A true NIB knife, second hand, should sell for a lower price than the same knife from a dealer.
A used knife, second hand, should sell for a significantly lower price than from a dealer. There are NO guarantees that the person you're dealing with is being genuine or honest - you should not have to pay a premium for that knife, when you could buy it from a dealer.
Collectors knives are more difficult, since they can no longer be obtained from a dealer. Price should be set by market conditions. However, the market cannot determine a fair price without fair information.
My suggestion is rate knives in the following way.
1) Most important: New or Used? Must be a very strict definition.
2) If not NIB, then rate the following:
a) edge condition
b) blade condition
c) handle condition
d) lock condition
e) clip condition
f) box/papers condition
3) Why are you selling it?
4) Blade type - Serrated, Partially Serrated, Plain edge
If the knife is truly NIB, you can not rate #2, because you have never handled the knife.
Also, I don't include an overall rating, because I think it is usually completely meaningless. Many listings on ebay say something to the effect of "Laptop - small crack on front of screen, case scratched, used for 2 years, overall A++++!!!!!!" Yeah, right. I'm sure it's better than perfect, especially after 2 years use and with cracks and scratches.
For a scale, I would suggest something along the lines of:
Very Fine, Fine, Good, Acceptable, Poor, Very Poor
So, for a factory perfect knife that was taken out of the plastic, used to open a box and a few letters, and put away, it would be:
1) Used
2)
a) edge condition: Fine
b) blade condition: Fine
...
Since the blade was used, and is no longer in factory shape, it probably is not Very fine. If the blade was looked at, but not used, it would be in Very fine shape. Knives that come from the factory with nicks, dings, etc, would also not be in Very Fine shape.
I always want to know why someone is selling a knife. If the reason is something like "failed the spinewhack test" - you might want to steer clear of it. If its because "had a baby, need cash", you probably don't need to worry as much about the condition of the knife.
Also, many people forget to list the blade type. This can be a PITA if you're looking for something specific. If it's listed, I know what I'm trying to buy.
Anyways, I could elaborate further, but you probably get my point.
--------------------
Prices on bladeforums/knifeforums/ebay/etc fluctuate wildly.
Factory knives that are commonly available sell for prices very much higher than they should because they are either misrepresented or the buyer is not aware of what the knife should be worth.
Knives also sell for far less than they are worth, hurting the seller, because even with high demand, many buyers are not willing to purchase a knife with the risks of 2nd hand, and would rather buy from a dealer. Unless, of course, there is a steep discount. This also hurts the dealers, because they can't compete with the steep discounts, which are often far below wholesale.
Prices should be somewhat standardized, especially on factory blades. For example, I should not be able to purchase a Spyderco Military in very fine condition for $60 shipped, but, given time, I bet I could. I have gotten even better deals in the past. Most internet dealers have it in the $100 range. While a military in very fine used condition should not be $100, or even $95, it should certainly not be at less than $80. A bluebook would be helpful, but lacking that, good descriptions will work.
Also, I would like to comment that listing MSRP is also misleading. Very few dealers sell knives for anywhere near MSRP, except in special cases. A listing like "LNIB Military, MSRP $157.95, your price $95" sounds like a good deal - after all, you're getting a used knife at 60% of MSRP. Really though, you're not getting much of a deal at all as you don't know the condition, why they're selling, what kind of edge, etc...
With a good rating system in place, prices would be more fair to the buyer, the seller, and dealers. We'd have less disputes, and overall would have less problems, and probably more buyers and sellers. Because the "for sale forums" are for paying members only, it might also increase the number of paid memberships.
Just my $.02.
-- Rob