Hi Elise. Nivea used to do an undereye cream for dark circles that was under a fiver but not sure if they still make it, tho tbh I'm not convinced creams make a difference

.
Alternatively, you could try using a light reflective concealer of which there are quite a few on the market. L'Oreal, Boots No7 and YSL make them (ranging in price from £7-£22 roughly) and no doubt there are other brands

. Hope you find something

.