Getting a striker like Haaland would be a miracle for PSG anyway. Things are not looking good at PSG at the moment. Especially after losing their important players, Mbappe will not be next year, so they will have to hold on tighter this year. This year may be better for PSG, of course, who will add to their squad during the interim transfer period, all will be shaped accordingly.
When it comes to Haaland he will have a release clause to be active next year. He will be able to be signed by spending 200 million euros if I'm not wrong. Haaland is also open to play for different teams throughout his career. Who knows maybe PSG can also try their luck with him.

But it depends on whether they will lose Mbappe next summer. Because for now there is still no progress on his contract extension. It won't be easy for PSG this time to convince him to stay longer. But they had better do their best because they are getting really weak without him for now.