I'm personally more of a collector than a user and over the course of my 5 year knife craze, here is what I have to share:
1. You should never "hoard" knives. Let me explain, working with a decently big budget that is at the same time limited, buy knives that don't drop in value right after you purchase them (most big brand standard model knives like ZT and BM) if you want to experience as many knives as possible without going broke. I tend to get either mid-tech/custom knives or limited edition knives if you can get a hold of them and try to flip them for some more profit so that you can buy more standard models without having your overall budget tank too much. At the very least, most mid-techs/custom knives retain their original value even if they are slightly used. Imho, spend 500 on a dope ass knife rather than 500 on 10 mediocre 50 dollar knife. 500 dollar knives really do feel different than 50 dollars knives.
2. Buy off forums like bladeforum. You can get LNIB knives which are practically off the shelf condition with a huge discount (for example, Chris Reeves knives are often 20~% off LNIB condition off forums). Definitely helps with the whole "experiencing as many knives as possible without hurting the budget pool" thing.
3. Trade knives as often as possible. You'd be surprised how much you can make profit wise if you find the right trade deal. My biggest swoop was being able to trade and make a profit in the triple digits, of course trades like these happen very rarely, but finding the right knives and the right collector who's looking for that knife is worthwhile. But the real purpose of trading is so that you can expose yourself to makers that you might have never considered. For example, I would have never tried a Jason Guthrie knife if it weren't for a trade. And boy was I missing out. It also helps with getting rid of knives that don't necessarily retain their value but are still sought after.
4. No matter what you read about knives and hear people saying about knives, nothing beats handling the knife in person.
5. With all that said, knife collecting is still a hobby and sometimes the budget pool is just gona have to take a hit when the right knife comes around. That's why you try scraping up profit where ever you can during the down season.
6. fk boker knives. (<- clearly my very bias opinion ;D)
Hope this helps I guess.