In my personal experience, not much although this varies from company to company. I’ve tried mascaras from all price points in my time but now it’s one make up item where I stick to drugstore. There are some excellent drugstore mascaras out there. There’s one high end brand (I shan’t name it because people seem to get offended if you hate a product they love) and every one of their mascaras have smudged and flaked on me. I do love YSL’s Faux Cils Effet but Falsifeye HD Mascara by Boots Seventeen gives me equally long lashes for a fraction of the price. If I have money to splurge on an item of makeup then I’d chose a lipstick or a cream blush (I’ve failed to find a drugstore cream blush that I totally love) but for mascara I’ll stick to drugstore. A few of my current favourites:

Maybelline Lash Sensation

Maybelline Push up angels

Boots No7 Velvet Lash

Boots No7 Lovely Lashes

Boots seventeen Falsifeye HD

My holy grail mascara of all time was drugstore, Maybelline Full n Soft, sadly it was discontinued in the UK a few years ago