Thanks for all your advice. I have decided to go for 2 lenses, but I see that it is harder to maintain and changing lens out door is not recommended?
If it were not recommended .. wouldn't every camera maker put countless advices into the manual? Common sense should tell you not to change the lens when lots of dust and dirt is flying around. But with a bit of practice it's easy. Don't rush. Dropping lenses does more damage than dust