I don't think Chelsea needs Erling Haaland at that huge price tag, he is a good player and can bring a difference to Chelsea attack this season but spending that much on him with some players rumored to be a part of swab deal is not a good deal. I feel they should go for the likes of Robert Lewandoski or Harry Keane if its possible.
Chelsea has a good experience coach that can lead them to premier league victory, they should utilize this transfer window before it closes to build a team no team would want to play against.
Let me put it this way, if you have the money for it, you can pay 500 million dollars for Haaland. Obviously nobody has that kind of money and nobody would be willing to pay that much because you can probably get him for 200 so why pay more even if you had the money. However the point here is that Haaland is very very young and he is already good, it is not like some young player who has higher potential or something, you get him and you play him and he will score on average once a game, sure there could be a game he doesn't score but there will be plenty he scores 2-3 goals easily.
This is why you get him, having a player for the next 10-12 years that will make you forget about the striker position worths a ton of money. Plus it is the most expensive position as well, he is scoring goals like crazy and that makes him more valuable than anyone else.