The mark-up at the store I went to seemed to be about 100% or more! By "mark-up" I mean the difference between what I would pay at a store and what I would pay online! I am not even talking about what they paid for the knife wholesale! If you factor that in, I wouldn't be surprised to find a few knives marked up 200%. I will pay more for the convinence of being able to take it home with me right away and being able to inspect it but I won't pay anything close to 100% more for that service.
I love guns as well and I have found that some gun stores charge way too much for their guns and I never buy anthing from them. Some store have high prices but once in a while they have something I want or have a deal on a gun and I buy from them. Some stores have low prices but little inventory so I don't stop by very often. I buy some guns online, some at gunshows, some at gunshops and some from private sales. I used to think the internet was the greatest thing but with high shipping and FFL fees, I can buy guns locally for a few dollars more but get to inspect them and take them home same day.
Depending on the gun, I think 10-30% mark-up is fair in order to handle it and take it home same day. New guns are less important to see first hand so I will pay less at a store for them than a used one. I think 10-20 markup is more like it in a new gun. I split up my money about even between, gunstore, gunshow, and online. Gunshow is either private sales or a FFL dealer that takes his stuff to the show so that is where the private sales come from.
A new knife is the same story. I will pay a premium for a knife I can walk into a store and buy but I am not going to be treated like a sucker. I think anytime someone trys to sell you a knife at 100-150% markup, they are calling you a sucker!