I saw this R1 and its sooo nice

But the only problem he said when its at high RPM in 2nd gear it will skip the gear...Now i have no idea what could be the problem..But its the bike i have always wanted and i have enough for it...
So could some1 help me out..I cant figure it out what the problem is...And he said that it has a clean title and everything he said also that it has been like that for like 2-3 years and no other problems idk