Small risk here, remember Vincenzo Fiorillo when Samp threw him in at 18 years old and he had that disastrous game? He has never recovered from that, and is rebuilding his career at just 22. Baby for a keeper, but they can be discarded too early.
At least for Leali he has played quite a few Serie B games and not only didn't look out of place but stood out. Serie A football is obviously of a higher standard, but a keeper still has to do the same things; make difficult saves, claim high balls, deal with physical strikers (more so in B, tbh) and command a defence. We wouldn't pay €5m for a young keeper we didn't feel could handle these things.