The 16/256 M4 MacBook Air costs 850€ including 19% vat here in DE, so your numbers are way off or you live somewhere with very unfortunate peicing in the eu.
Certainly not from the Apple Store, where it's 1.199,00€.
Cheapest, I found was about 1000€. Buying a one-off offer from some random webshop, means you would have to deal with them in case of repairs or warranty issues.
And yeah, effectively max. 200GB non-upgradable SSD storage, certainly makes cheap offers likely, cause that's borderline unusable for almost everyone, who needs more than a web browser.
