I'm not sure about the money but single bucking was the most popular in the pacific NW. In the East it seems that double bucking was the standard. Part if the issue was that some logs were simply too large to double buck.
Three buckers, three saws:
Single underbucking, no double bucking here:
The left hand drift that I have seen is not enough to cause a bind so the alternating teeth should not cause a problem. This was a 24" log"
A left handed person does stand on the right hand side of the saw. A good bucker should be able the saw with the right or left hand the dominant hand. You can switch off hands/arms if one gets tired and sometimes there is an obstruction that limits the sawing position to one hand or the other. It is a little odd at first but after you do it enough it feels okay with both hands. In the case of a single bucking saw cutting a little to the left, it makes no difference what hand is used.