I think prostitution has many stratas, much like the society in which it operates.
At the top are women totally in control of their lives, making a lot of money, at the bottom are drug addicts being used and abused - and there is every permutation inbetween.
As to whether it is easier or harder than a 'day job' rather depends on the circumstances, and the attitude of the woman involved. If she is in control, and has a detached 'professional' approach, then fine, if she is deparate with nothing else to sell except herself, than that is a different concept entirely.
My personal vierw is that it should be legalised now.
Society doesn't have a choice about having prostitution - it is here to stay, the only choice is whether society adopts a degree of control, or not. Control means safety for the women involved, and specific areas where it can be carried out - industrial estates for example, which negates the problem of red light residential areas.
It is a contentious issue, but it is time we stopped being Victorian about it, and started looking at the realities involved.