Actualy, not neccesarily true. I carry a Buck Ti even though I could buy a much more expensive knife and I do carry and use a $300 fixed. I don't buy a more expensive knife because I don't have to. There is nothing at any price on any market that I would be more confident with. I have used my Buck Ti extensively, and like all my Buck lockbacks, it's never let me down. Sharp/sharpenable, awesome grip rentention, great shape, great size, the bolster forms an excelent gaurd, this knife just kicks!
Anyway, I have often bought Buck's that had some weird goo in them when new. Work the lock back and forth a whole lot and see if you can work anything out/see anything. Also check to see if it has a lot of crud in it. I don't know how this happens, but it's not uncommon. Once you clean them thoroughly, they work great.
#2, oil it. Lockbacks like oil a lot. Three-in-ones and light machine oils work great. I've used corn oil when I didn't have anything else, but it gets goopy after a while and needs to be cleaned.
As suggested, lockbacks to stay closed with a little more gumption than liner's, but nothing I'd call hard to open. The flip side is they stay locked with more vigor than do liners. A good lockback won't let you down. This one is one of the best you can buy. There may be locks with more paper strength, but I have never had a lockback fail on me...
Oh, if you want some "quickdraw" tips, check out the "Prevelance of Buck 110" thread in the general forum.
This is a great knife, once you get used to it, it won't let you down. The best Buck has ever made.(can you tell I like these?)