Upon graduation from seminary, I ministered full time with full salary. 60-hour week was the norm. When I later began "mission" work with small churches or founding churches or even in my last 15 year pastorate in church I founded, I was on a love-offering (to help defray expenses, $100 a week from the church was the norm. I taught college classes, wrote books, worked for organizations.
I could NOT have ministered as effectively in my first 25 years of ministry with small children and needs of family. I feel it is hard enough if you are truly invested in ministry WITHOUT adding a second job. That changed the last 25 years in ministry as children were grown/gone, wife working, house paid for, and social security/medicare.
LOTS of different factors than apostolic times. Growing up Jewish the idea of our reb working at more than our congregation would be anathema. Our rule was if congregation had 10 tithing families, this equaled the "average" salary of the rabbi. Then HIS tithe would pay for supplies/utilities for the meeting house. It worked well. We taught men to do the same today in our State Baptist mission work.