||- NO, Virtual Airlines do not cost any money. At least, I have never heard of something like that and would advise you that if you are ever required to invest any money for any reason, that you do not join that VA. VA's are run by and for flightsim enthusiasts to create a realistic and pleasant flying club/ flying environment and just to have fun.
- NO, normally you cannot earn any real money. Again, it's a hobby, not a real job. You don't fly real paying passengers or real cargo. Sometimes VA's pay you virtual money, just to increase the realistic feeling of an airline.