Here's the deets as far as price and size:
Shape Tape - $24 for 0.338 oz
Creaseless - $26 for 0.225 oz
NARS (Radiant Creamy Concealer) - 0.22 oz, and I lost the price but it was over $30 and I'm not looking it up again right now!
Sephora seems to be hiding the size, at least on the Tarte concealer - maybe because they don't carry ShapeTape? That information comes from the Tarte website for the two Tarte concealers. The Nars one I was able to find on Sephora's website. (I'm sure it was somewhere on Sephora's website for Tarte Creaseless as well, but it was well-hidden enough that I didn't find it and I got pissed off and switched to Tarte's website instead. It's pretty hidden there too, actually, but I went through this when I bought concealer there before and I remembered to look under "ingredients" - which makes no sense, really, but whatever. If a lot of people cared I guess they'd be putting it somewhere more easily findable.)
So ounce for ounce, you want Shape Tape. Of course if you really pick your concealer ounce for ounce, you probably want e.l.f. or Wet n Wild or somebody like that. (Maybe Colourpop, I've heard good things about that one.) So really this is the higher-end concealer battle, I guess.
Anyway, I like the Nars concealer a lot, but not really any better than Shape Tape. I bought the creaseless one, too, but I haven't used it a lot so far. (At a guess, I'd say it will end up in my purse when the Maybelline one that's in there runs out.) Kathleen Lights raves about Jouer's concealer but I probably won't get around to trying that one any time soon. These three are just the ones that are super-popular and that I have.
I've probably mentioned this before, but besides the fact that I seem to buy a different brand of concealer every time, I am now in flux about what color to buy. I definitely think that the old wisdom (or not-really-wisdom) about buying your concealer lighter than your skin is stupid, but I'm having trouble finding the right color. I deliberately bought the Shape Tape darker, and I still think it's too light. I do still mix it with the LAGirl apricot one some of the time too, though, so there's that. I don't think this is an issue that's going to get miraculously solved any time soon.