I really recommend Colourpop. It sells in Europe only through the webpage, but It’s worth it + they have many great online offers. ELF is also great. So is KIKO. Some products from makeup revolution also work great, especially the new eyeshadow pallets.
As a general recommendation, I would advice always buying cheaper mascaras and brow products because the quality difference is not perceptible . You can also find really good eyeliners, blushes, lipglosses and satin lipsticks in the cheaper end. For products that go directly on the face, such as primers and foundations, the cheapest I would go are pharmacy brands such as Avene.
Hope that was helpful 😊