Carmela, think of it sort of like a rate card. We have hourly rates on our profiles, but that isn't always useful to a client, because inexperienced clients may have no idea how long a certain type of project will take. Not everyone offers services that can be fit into this type of boxes, but for those who do it can be a useful way to let the client get an idea of what his project costs, rather than just what your time costs.
For instance, I write a lot of blog posts for consumer law firms. Though there are occasional exceptions, those posts are pretty much standard in terms of time commitment and process, and I routinely offer them on a fixed price basis. For some clients, it's more useful to look at my profile and see, "A blog post of 600-800 words typically costs X" than, "Her hourly rate is $YZB"
I'm also hopeful that the project pricing will be harder to ignore than hourly rates seem to have been and will cut back on clients sending invitations that are far, far below the freelancers rates. But, that remains to be seen, based in part on whether freelancers lie about the stuff in those boxes the way many do about their hourly rates.
The "starting at" and "request a quote" protect you from a client just placing an order that doesn't really fit in the box and should have been more expensive.
