I used to buy two of everything that I liked, one to carry and one to keep "in case I lost the carry one". Then I got on a carbon fiber kick, then a titanium frame lock kick, then a newer super steel kick, to go along with my addiction to auto's so I ended up with quite a few more than I realized after going through my closet during some off time during the Holidays so I have been culling the herd.
I now have about 40 quality folders and auto's, the lowest one is a S30V blem Blur (the one that got me back into knives), and then most are $150-$240 range with a few smaller fixed blades mixed in (got on a TOPS kick, too, that I have now mostly liquidated). I am an accountant so I have a spreadsheet with my cost in each knife and it is over $10k so I am still selling when I can find the right buyer. I typically to a sell to a specific distributor at gun shows who pays me realistic prices or to people that I know.
I now only buy LNIB used at a fair price and try to abstain whenever possible, i.e. the nice lot including the Ritter Grip with Wilkins folder for sale right now on the exchange. I really like the Grip but know that I will never carry it.
My most expensive right now are a couple of MT QD Scarabs, Strider SMF's, and a Strider SJ75 that I just got that I had to buy. I am in the process of moving the SMF's and maybe the Scarab that I do not carry.