I am like Mary, my experience is limited to middle eastern churches, but not all orthodox preists are married though, but either way, his salary depends on some percentage of the parish income, and the percentage varies on wehter he is married or no, how many kids he got, the cost of living in the country and in the city he is in. Some times it is hard for them to keep up , for example in jordan, the syriac catholic church gave the syriac orthodox church money whenever they needed, even though our preist was not getting payed that much, but people from both churches worked together to keep our churches open and fight the ethnic and religious persecution. And out Partriachs have been in close contact, so over all , it is a percentage and it depends on factors.
And as far as i know, catholic preists can not have a job outside the church, but they can volunteer for works, but it must be through the church.
and Sister Mary, orthodox churhes are mostly saperate, and they might have different rules regarding this issue, but i have no information about it,