My two favorite brushes that I use to apply eyeshadow on the lid area...are not actually lid brushes! Of all my beauty items I think the thing I have the least of is brushes. I often get so excited about new eyeshadow and lipstick colors I neglect building my brush collection. So I am always on the lookout for good quality brushes that are inexpensive.
Right now I am loving the 1/2 Loew Cornell 270 Maxine's Mop (actually a paintbrush) and the Makeup Geek Mini Concealer brush. They are both flat shader brushes great for packing on color and are around 5 dollars. I like the Maxine Mop for when I want to do an all over wash of color. The bristles are dense but soft and I also think this would work great for large eyes. I got mine at Michael's, but I think you could find it at most craft stores. The MUG brush is great for all eye sizes and I really like it for more detailed work. I use this brush to apply paint pots and other cream products quite often too.
I have heard the mini concealer is a dupe for the MAC #239 but I am not positive because I don't own it. I own for the most part Sonia Kashuk and ELF Brushes, along with some miscellaneous Sephora ones and paintbrushes. To me, if it works and is of good quality, that's what is most important. Not a high-end price tag. That's not to say that I wouldn't like more MAC brushes: I would love some! But it's also nice to save money :)