The difference in the scales of prices prevailing at any time in the cheapest and the dearest local markets was hardly ever less than thirty per cent.

From such a margin, however, there had to be deducted not only the cost of feeding, clothing, sheltering, guarding and transporting the slaves for the several months commonly elapsing between purchase and sale in the trade, but also allowances for such loss as might occur in transit by death, illness, accident or escape.

At some periods, furthermore, slave prices fell so rapidly that the prospect of profit for the speculator vanished.

At Columbus, Georgia, in December, 1844, for example, it was reported that a coffle from North Carolina had been marched back for want of buyers.[40] But losses of this sort were more than offset in the long run by the upward trend of prices which was in effect throughout the most of the ante-bellum period.

The Southern planters sometimes cut into the business of the traders by going to the border states to buy and bring home in person the slaves they needed.[41] The building of railways speeded the journeys and correspondingly reduced the costs.