Content can be provided by either the client, agency or a contracted third party. Ideally, both client and agency will play some part in content creation and review.
A good copywriter can budget this in around 3-4 hours with up to two rounds of revisions for a non-article page. If a client plays a larger role in this process it may delay the project.
Tips: Having a trusted copywriter on board at the beginning of your project is crucial for avoiding website launch delays. A copywriter will be used to working with deadlines, and the requirements of website design (ex: limited character counts, calls to action, SEO). An internal writer or assigned staff member will often not have this experience or understanding of the project, which can lead to delays, or increased back and forth with the design team.