Is Messi 50 goals away from overtaking Pele to become the greatest ever player in history?

Despite the fact Romario boasted at the end of his career to have scored more than 1000 goals, everyone trusts more the number achieved by Pele. The Brazilian star scored 643 goals for Santos and has the record for the number of goals scored in the same club, something which Romario, one of football's globetrotters, cannot aspire to.
Messi can do that. The Argentine scored a brace against Espanyol although the first goal still creates debate on whether it is his or not and he is just 50 goals off with which today he is considered one of the greatest players in history. The present campaign has been very interesting for Messi in this aspect. Despite the defeat against Betis in the first half of the season, he was able to go post Gerd Muller's tally, another footballer who scored lots of goals at just one club.
After his goals against Betis, Messi reached 566 goals, one more than than Muller got at his years at Bayern Munich. Various months later, the German stayed back and Messi is now looking towards a greater challenge. Pele, with his 643, only has 50 more than Messi at Barcelona. He will not go past him this season, but everything seems to indicate he will do so next season and in the worst case scenario, the one after.
Although stars like Casillas have hinted that records like those which the Argentine has achieved will be beaten in the future, the truth is the record which Messi could break recording the number of goals at one club would be something really special.
The globalisation of football, which invites players to change team frequently, makes it very difficult for anyone to have a such a great career at one team like Pele and Messi did. What is also true is players like these two do not come round every day.