MAC's Candy Yum-Yum is definitely one of those cult favorite lipsticks, so much so that it was one of the three shades brought back (for a limited time, of course) in MAC By Request in August 2012.
Candy Yum-Yum is a matte finish but it applies very smoothly and opaquely. It is described by MAC as a "neon pink" which is pretty spot on. It leans blue, but not terribly so.
MAC recently had their price hike, so lipsticks are now $15 each and it's up to the consumer to decide if it's worth it. This shade doesn't strike me as particularly original and I think you can find a number of dupes in a much more affordable range. The finish, however, is not as common in drug store ranges. It's a matte finish so the wear time is really good (I got around 6 hours out of it). It can be a little drying, but it wasn't anywhere near as bad as I was expecting.
In my experience, quite a few drug store formulas can match the shade, but finding one that will match the shade and the finish is much more rare, however there is one. NYX's Matte Lipstick in Shocking Pink is a really close dupe for both color (it's slightly more blue, but only slightly) and finish (they're both matte).
If you're just looking for a color match, NYX's black label Hot Pink (Phyrra did an excellent post on Candy Yum-Yum vs. NYX's Hot Pink) and Wet n Wild's Nouveau Pink #511B are both fairly close color matches.
What do you think? Will you be picking this up while it's available? Will you go for a more affordable dupe? Is this color one you will pass on?
Given that the NYX Shocking Pink is such a good dupe, I don't think I would necessarily pick this one up again (even if it was available).