Negotiating an offer, is it too late? (update)

It is the first offer in 6 months and I do not want to mess it up. It has been a long 16 weeks. I have a competing interview next week.

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.