100m is a huge sum of money, and do you really think prices will be higher than before covid?
especially if he's available next season for a lot less, I don't see it climbing that high personally.
COVID discount doesn't apply to players like Haaland, Mbappe and Sancho due to their age and guaranteed potential. Haaland's value now on Transfermarkt for starters is €110m and counting by the summer it'll be closer to €150m with 3 years left on his deal so from a business perspective selling him for €100m is bonkers it's a huge depreciation on his value.
Factor in how important he is to BVB and how stubborn they are with prices remember €120m or nothing with Sancho and Haaland is a bigger talent mind you?
Also if they get CL football(they are just 4 points off a CL place) and how they are a PR team do you really think they'll sell Sancho and Haaland in the same window? It'll be disastrous for their image having him for an extra season with Marco Rose and a rebuild from funds they'll get for Sancho will put them closer to Bayern, give them a good chance of getting far in the CL and maybe win a Trophy. All those reasons makes it very unlikely they sell Haaland cheaply