I'm 10000000% certain that messi would score at least 10-15 goals more in bpl.
I don't know how much Messi would score in the EPL, but if Suarez could score that many with Liverpool, or Aguero average a goal a game in the last two seasons, and Harry Kane could score so much with Spurs etc etc etc, then we all get the picture I guess.
I heard people say that since Chelsea have scored only 73 goals in this year's EPL, and Barca/Real scored over 100 in La Liga, then that is some kind of definitive proof that the EPL is better. Well, if that is not some kind of false equivalence, then I don't know what is. By drawing such a conclusion, then one obviously assumes that Barca/Real forward lines are equal to Chelsea forward line. Well let's see. Messi-Suarez-Neymar vs Hazard-Costa (several injuries and suspensions) Remy? - Drogba? Or the aforementioned Chelsea forwards vs CR7-Benzema-Bale-James. Obviously the teams with Messi, CR7, Suarez, Benzema, Neymar, Bale and James will outscore (massively) a forward line with what Chelsea possesses. City managed to score 83 goals with Aguero half-fit, and also contributions from Dzeko, Bony and a few midfielders. Last season, both City and Liverpool scored over 100 goals each (a bit more than we did in 13/14) with forward lines far inferior to what we and Real Madrid now possess.
Hence, the much-recycled notion that it is harder to score in the EPL can easily be destroyed.