Makeup

So, I have pretty uneven skin. I have psoriasis, so occasionally it flares up and causes the bumps/scales. It is pretty rare on my face though. I also have bad scarring from acne on my cheeks(no longer have it).

I used to use lancome, but honestly I can't afford it now..

What's a good concealer and foundation for combination skin (that won't cause oilyness) that is under $30?

And am I totally out of my mind thinking I can ever do that blending stuff with the sponges???