Negotiating an offer, is it too late?

I received an offer as a copywriter and I think the pay is a little low. Thank you in advance. The hiring manager was friendly and open.

I thanked them and said I was excited but hoped we could talk about the pay. They came back with a bit more.

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.