Online you'll always find better prices, that's almost certain. Amazon, PCComponentes, Coolmod, CeX... have way better deals than big physical stores. Media Markt and Carrefour inflate prices because they need to cover store costs, so it's normal. What I'd recommend is searching several sites at once, because prices change almost every week and sometimes there are surprise discount codes.
With 80 euros you have decent options. Look at lesser-known brands that work well: Corsair has some basic models that fit the budget, HyperX too (though their prices went up a while back), and then you've got Chinese alternatives like Picun or LEDGER that surprise you with their value for money. They won't be high-end, obviously, but for Baldur's Gate and Palworld they're more than enough. What matters is that they have at least minimum passive noise cancellation, a decent mic, and that they're comfortable because you'll be wearing them for hours.
My advice: buy from a place with a good return policy just in case. Amazon and PCComponentes give you 30 days, so you've got time to try them at home and send them back if you're not happy. And wait for sales - usually in August-September there's stock movement and prices drop.