I did that! .. Recently I decided to buy a new knife,, the first decision was what company or maker I would buy from , and then what type... I didn't have a tanto,, so I bought one. as far as materials go,, I just choose materials for what best fits the funtion of the particular knife.
I would like to have a wide variety of knives.. but all ones that I really like,, I wouldn't buy a knife just because everybody likes them and they are really popular.. for example.. if "fantasy" knives were suddenly all the rage.. I still would never buy them.
I have an intrest in combat knives, The tougher the better, so that's what my collection consists of.. and one folder.

I would like to get a really mean fighter next. I think it would be fun to practice knife fighting... It's hard to decide which one to get though,, you can't go by what the company says about their knives.. they all talk a good game..Hell you can HIRE someone to talk a good game for you if you can't! I think you have to go by what actual owners think of them. that's what blade forums are so good for.