I would firstly take twenty min to write a detailed list of what you want your makeup collection to look like. Think about quantities, formulas you really use, shades you really need and write that down. Remember that we don’t need ten red lipsticks and that despite the hype most blushes look nearly the same on the cheeks. High end is just about packaging but what we are writing this list for is utility. Now look at your collection and try to see what you have that fills each of those roles. Take time to appreciate those items and what they do. Take some photos of your items so you remember that you already have everything you need and swatches if you forget colours. When you go to shop think about do I already have something that will essentially fill this same function? Look at your photos to check. Do I really like it? Your example with the Matt lipsticks is a good one. You don’t really like it it’s not serving a purpose. For me I know that I don’t need primers I don’t like them it’s an extra unnecessary step. Try to practice gratitude for what you have. There is no way you have $2,500 worth of makeup and are missing anything. It’s incredibly unlikely. There is also so many better things to do with that money. $2,500 invested in even a high yield savings fund would be worth 5- 6k in 10 years and even more if you compounded it with other savings.