if your work is passport portraits or similar it might work, but usually no job is like the other, so an individual quote is a must. I only give a quote on written request, and always in writing, always a pdf and not a inline email. When someone calls me about a job, I discuss the requirements and then ask for a brief email to pin that down. Never, ever do I tell things like creative fees or usage fees orally. If a client is not willing to write a five line email, I doubt they are serious about their enquiry. this strategy saved my arse a couple of times, which is more worth than one or two jobs which I didn't get.