Most work in the early ecclesias, whether by brothers or sisters, was obviously done voluntarily and without payment, because of their commitment to the new life in Christ.  The apostle Paul was self-supporting and current Christadelphian practice, where work and time is freely given is a sound principle.  The practice elsewhere, however, of paying full-time church workers also draws its support from the New Testament.  It is implied in Galatians:

Let him who is taught the word share all good things with him who teaches.                                                                                   (Galatians 6:6)

This did not specify any particular financial arrangement, and was based upon a position where wealthy people in the ecclesia would be receiving instruction from those who were poor.  The principle is there nevertheless and is more specifically stated in 1 Corinthians 9.

Do we not have the right to our food and drink? ... Or is it only Barnabas and I who have no right to refrain from working for a living?  Who serves as a soldier at his own expense? ... If we have sown spiritual good among you, is it too much if we reap your material benefits?  If others share this rightful claim upon you, do not we still more?

Nevertheless we have not made use of this right... ... the Lord commanded that those who proclaim the gospel should get their living by the gospel.

But I have made no use of any of these rights....        (1 Corinthians 9:4-14)

Paul placed himself in a special position.  The normal position appeared to be that those who preached were maintained by the ecclesias.  The command from Jesus which Paul mentioned is in the instructions given to the seventy disciples in Luke 10:7-8:

... remain in the same house, eating and drinking what they provide, for the labourer deserves his wages;  do not go from house to house.  Whenever you enter a town and they receive you, eat what is set before you.... 

In 1 Timothy payment was assumed for elders while those who “rule well” and “especially those who labour in preaching and teaching” were to receive extra:

Let the elders who rule well be considered worthy of double honour, especially those who labour in preaching and teaching; for the scripture says, “You shall not muzzle an ox when it is treading out the grain,” and, “The labourer deserves his wages.”                                  (1 Timothy 5:17-18)

“Worthy of double honour” does not seem merely to mean “worthy of double respect”, as Paul goes on to illustrate. The Revised English Bible translates the phrase: “... worthy of a double stipend”, and the Good News Bible says: “... worthy of receiving double pay”.  It is not clear what “double pay” means. Is it double the amount paid to all the other elders? Or double the pay other ecclesial workers receive? Or is it double the amount they were receiving up to that point – a special short-term measure to arrange for good people to take charge in Ephesus and to sort out the problems which Paul had sent Timothy to solve? 

Payment enables more time and energy to be devoted to ecclesial service and although there are disadvantages in selecting one or two individuals and paying them to do full-time Christian work, the New Testament clearly favours this in principle.