His market value is currently 82 Million Euros, so 100 Million Euros for Rashford isn't really high.
Honestly, I am not sure if Rashford is really valued close to £100 million. According to transfermarkt, his highest market value is £85 million. And now it even dropped to £60 million. I think the offer £75 million should be enough for Rashford but Man United must expect higher transfer fees. I think £85 million can be tempting Man United.
Regarding Yamal, it doesn't make sense if barcelona wants £200 million. Is he in the same level with Mbappe and Osimhen? I think his level is much lower than superstar players like Mbappe and Osimhen.
Please take a look:
1. https://www.transfermarkt.com/marcus-rashford/profil/spieler/258923
2. https://www.mirror.co.uk/sport/football/transfer-news/marcus-rashford-transfer-psg-manutd-32345657
3. https://www.eurosport.com/football/transfers/2023-2024/paris-saint-germain-plot-75-million-move-for-manchester-united-forward-marcus-rashford-paper-round_sto10060696/story.shtml