imho in production knives, the one that holds value best is either emerson or microtech, but they cant be std models, example - the microtech SOCOM elite M/A holds its value well, as does the EKI CQC8 surefire combo, either one of these knives, kept in LNIB condition, will prob not LOSE money, might not make $$, and also ya have to buy them right, ie dont pay retail!!
some BM/spydie prototypes/limited editions are ok, but imho the std models are really users only, unless ya collect them, i collect BM's but i dont think i will make $$ doing it, strictly for fun
i have a bunch of old BM's (ie spike/leapord/AFCK/emerson design) that i bought for $50 to $60, and they are still worth, well, $50 or $60 bucks, or so.......
imho if ya want to not lose $$, pick a good custom maker, and get one of his products, use it, if ya wanna sell, have him recondition it, and if its a ralph/mayo/etc, ya will get your $$ back outta it, unless ya mess the thing up BAD were the maker cant get it in LNIB condition, i had a crawford KFF, used it hard for a yr or so, and pat re-did it to LNIB shape for less than $30!!
greg