I only worry about overpaying for a player if that overpayment meant that we had to take a pass on another player we desperately needed.
As for Hojlund himself, he comes to OT as a virtual unknown footballer with the promise of a lot of potential. I doubt a single caf poster expects the boy to score 20+ in his first season, but at the same time we do have to expect fairly immediate returns at least in terms of creating chances, opening space for Antony and Rashford to exploit, and scoring a few goals here and there.
For me it's a real shame we couldn't have used the cash that we demonstrably do have in the budget to bring in a proven striker-- by far and away our most glaring hole in the squad. We have a squad that's ready to challenge for the PL title now, not in 2-3 seasons. In 2-3 seasons we'll see peak Hojlund but Casemiro and Varane will be gone, Bruno will be past peak and Shaw will be past peak. Maybe we'll replace all four in 2-3 years, but these four players are at a point in their careers where they can form the spine of a proper challenge for every trophy and to bring in a striker who will probably take 2-3 years to hit his peak means in all likelihood not winning a major trophy -- for me, if you don't have a proven striker you are not winning a major trophy -- while we still have these four incredible footballers.