These Alabamians are generally men of wealth, and they insist upon bearing their own expenses.--They say they came to Virginia to fight for her citizens who are their brethren, and not to put them to expense. They are in for the war.
On the issue of pay, there's no reason to believe that volunteers of the early war period paid their own expenses and/or refused to accept payment from the Confederate government. Also, these were twelve-month volunteers. Popular opinion held that actual warfare would last for a short period only, so the writer may have been suggesting that a twelve-month volunteer was "in for the war."
With regard to "these poor negroes," pay receipts for Alabama officers issued a few weeks earlier are educational. On Mar 2, 1861, officers of seven Alabama companies who occupied Fort Morgan and the arsenal at Mount Vernon received pay for service. In addition to regular pay, all twenty-nine captains and lieutenants received addtional pay for a servant at eleven dollars a month, plus $2.50 a month for clothing and sixty cents a day for subsistence. The form reads, "Servant (not a soldier)."
Each form includes a box for the servant's name. Additional boxes are for height, complexion and hair color. One servant has both first and last name, which suggests a free person of color who has been hired as a servant. Most of these officers do not appear to have owned slaves, so several other servants could have been hired from their owners. Complexion of two servants is given as white, so these two officers must have hired free white men or boys.
The government issued a single check, so each officer pocketed the money allowed for his servant. Of course servants could have been paid more than the government allowed, but I rather doubt it. At this stage of the war, an officer who had a servant to cook and do laundry for him could expect to make a little money for himself.
If there really were as many "poor negroes" in the camp of the 4th Alabama Regiment as claimed, nearly all of them must have been officer servants. A few more might have been brought from home to cook for enlisted men, and others could have been hired in Virginia.
Even for May 17, 1861 (the regiment entered Confederate service at Lynchburg VA on May 4, 1861), 1,254 officers and men is a high number. There would not have been that many names on ten company rolls, present and absent. The regiment took roughly 700 into battle at Manassas, so 850 PFD would be more accurate.
Results of the pay receipt review for the Alabama officers mentioned above are listed on the Alabama Message Board.