I buy, sell, and trade knives of all kinds. I guess that's my hobby "on the side" - LOL!
No, but really, if I see a knife that I want to try, I'll just sell-off or trade-away something(s) not being used or otherwise enjoyed. That way, the collection is constantly changing, and I get to try even more knives than I would if I kept everything I acquired all the time.
I would like my collection to get to that point but I have to invest a lot more money in it because I currently only own 10 knives and I don't want to give any of them up!