How much room is there after an offer? - 5 months and counting

It is the first offer in 5 months and I do not want to mess it up. I am in Boston, in case local advice matters. The hiring manager was friendly and open.

If they say no, consider asking for something else, such as a review in six months.

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