i've never worked a knife counter, but allow me to say one thing. Be careful. I've turned things that i absolutely love into retail jobs before, and let me tell ya, it's a double edged sword. On the one hand, you'll probably get some discounts or ordering access you wouldn't have as an every day joe. You'll also get the chance to handle a lot of knives without having to buy them, and you'll get to chat about knives all day, which is kinda what we do on here all day anyway. Additionally, these jobs are usually relatively low stress, especially as part time.
On the other hand, you'll have to deal with the subsidiary position in the workfield. I.e. You'll have some guy who may or may not have so much as a backbone ordering you to do this and that, and do it now, and do it better. Those people you'll get to chat knives with all day long? Many, if not most of them will be complete or at least relative morons. You'll often give the same speeches so often you'll go blue in the face. You'll recommend quality knives and many, if not most people will generally say thanks, but i'd rather go with a cheap piece of crap. Finally, you run the biggest risk of all....getting tired of dealing with knives. It's true. There is the possibility (not a certainty) of dealing with the same crap so much that you'll no longer want to come home and look at or buy new knives, or worse yet, you could not even want to come talk to the kickin' folks here on bf!!!!
Terrifying thoughts, i know, but assuming it's part time, you'll probably enjoy the experience, as you'll have breaks throughout the week from the "grind". The thing to remember is, you can quit anytime if it gets to be too much, so in reality, there's no worries!