Is BudgetAir worth it if I'm saving 400€ ?

Hey, I’m planning a trip to China and the round flights for the dates I wanted were around €750 per person.

I’ve been checking several nearby dates too, one day before/after, and prices were basically the same. But by chance I found that a couple of days after the date I had almost decided on, the flights were about €200 cheaper per person.

The issue is that this cheaper price only appears with BudgetAir. On the other dates, BudgetAir is priced the same as Trip.com and other providers, but on this specific day it’s €200 cheaper per person.

I’m tempted to take it, because we’re two people and saving €400 total is a lot, €1,100 instead of €1,500 makes a big difference. But I’ve seen that BudgetAir reviews are really, really bad.

Has anyone here booked flights through BudgetAir before? Do you think it’s worth the risk for a €400 saving, or should I avoid it and pay more through another provider?