In this post I'm not talking about just buying something to use for a different purpose than the one for which it's advertised. So you might buy a darker shade of pressed powder and use it for contouring, but since you're presumably not using it as all-over powder too, you're not doubling up. I'm talking about products that you can use for their intended purpose and a secondary one (or more).
I've discovered a particularly exciting example recently (at least for me). It involves the wonderful Milani Shadow Eyez in neutral matte shades that came out in the spring. They're limited edition, but I saw them only a week ago at my local CVS, and you can get them online at from Cherry Culture and elsewhere. The one called Almond Cream makes a nice light base shadow, and you can check out swatches and a review of all of them in their intended use as eyeshadow from Nouveau Cheap.
| Milani Shadow Eyez in Almond Cream and L'Oreal True Match Super Blendable Crayon Concealer in Fair/Light |