At 19 years of age Neymar was scoring 43 goals in 47 games for Santos. You're massively overrating Sancho if you think he's at that level at present. I think he can produce world class numbers at the highest level at some point in his career, but I think sooner rather than later he's going to have to move to a club where he'll have to fight for his place.
At Sancho’s age Neymar had 79 games for Santos, scored 36 goals and assisted 21 and most of Neymar’s goals came in the Campeonato Paulista, a pre-season type of competition which Pele scored 466 goals in.
Here are both records at same ages.
Neymar (Matches/Goals/Assists):
Club: 79 36 21
NT: 9 5 1
Sancho (Matches/Goals/Assists):
Club: 55 14 23
NT: 8 2 3
Quite similar, but i don’t think it’s not unfair to say Sancho is playing at a higher level than Neymar was, Sancho is currently playing his trade in a top 5 league in the world (imo 3rd best league) and regularly in the best competition in the world (Champions League).
At Dortmund he pops up in vital moments to score goals and register assists, but he doesn't dominate games the way his talent level suggests that he could. He's still
The guy's just started his career, so you can't expect him to do that, in the same way C.Ronaldo/Messi never did at 18/19. But Sancho has made a goal or an assist every 0.67 matches on average for Dortmund which says he has an impact on a match every 67 mins on average.
I don’t think he had his best game against Barcelona, but won a penalty and should have scored.
Fees of £150 million for him are not being thrown about for him as a joke and clubs aren't willing to pay that figure for a laugh, that figure is being thrown around and clubs are willing to pay it because he’s a little bit good and at only 19 years of age as potential to be one of the best players in the world.