Agreed, £50m looks too small for Lookman, but Atalanta was a club that often increase the price of its player. Since no serious interest come for him, and it's free for them to increase his price. He's solid forward, and any club that will get him as a new forward is good.
The problem is that £50m still relatively big for some club such as Inter Milan or even Barcelona. I think other clubs may be thinking for twice in getting him with such price.
It's also possible for him to stay much longer there if he still gets no club till the end of summer window.
You remember when Rasmus Hojlund was sought after by Man UTD, how much did the English club pay for him? Over a£100m plus and it's not like the Danish player was better than Lookman but it gets to his (Ademola) turn, they reduce the price. Is it because they are trying to punish him for a mistake he doesn't know about or they are really desperate to offload him from their team? Believe you me, if he eventually enters any other Italian outfit, I bet you he'd gladly wreak havoc on Atalanta should they meet.
For now, it's just Inter that's the Italian team that we've heard about coming for the Nigerian and like you said the club may think to reduce his asking price if they don't get much offers.