Dreamweapon: I do know, but I'd rather keep the DS4 on my PS4 (I have one of those too) and the disadvantage of a DS4 is you CAN'T turn the PS3 off with it, or so I understand it. So I'd rather keep that as a last resort. (At least I still have a working DS3 on my PS3; I'm just thinking of future when it breaks. If the one I'm using on the PC breaks, I'll proly swap to a DS4 or a Xbox controller there, but that's the PC. I have more options on the PC.)
Also if you have said DS4 synced to your PS4, some funky things can happen, like you buying stuff on the PS4 you didn't mean to! No thanks there. Also I've never been bothered by the DS3, I actually find both DS3's and DS4's rather comfortable in their own ways. Hence, why I have one on my PC at the moment. ^^
Since they are no longer making PS3s, I really think I can't find new DS3's anymore easily, that's why I was asking about the used market. ^^
Also I bought This recently so I could charge my DS4/DS3 without plugging either into either console, so battery life isn't that huge a issue now for me. For the rest of you CAGs; it DOES work with a DS4 as well, tho it says DS3 charger.
And Doh; I wish I'd had your foresight. I didn't think about it when you still could get DS3's without worrying about knockoffs; now if you're looking at new ones, you might be looking at a frickin' knockoff. (Which is why I'm going to avoid online if I find I actually need a new-to-me DS3. Easier to tell if it's a fake if you can see/hold it I think.) I just don't trust knockoffs when it comes to console controllers.