How come I never have problems like this? I could spend $60,000 and not even make a dent in my "Wish List". Every time I think I have a handle on what I'm going to buy next something else pops up.
You have $600 and no idea what to buy? I don't have a clue as to what you're into (production or handmade, fixed or folders, tactical or traditional) or how many knives you have? If it were me I'd only be looking at customs.
Good luck.