This paper explores the value, benefits, and concerns of generative AI-powered assistance in writing. The authors conducted a randomized human-subject experiment to understand people's attitudes and experiences with AI-assisted writing. The study found that participants were willing to forgo financial payments to receive AI assistance, especially when AI could provide direct content generation assistance and the task was highly creative. AI-powered assistance increased productivity and confidence in writing but also decreased accountability and diversity in writing. The results suggest that the perceived financial value of AI assistance varies with the type of assistance and the nature of the writing task. The study concludes by discussing the implications of these findings for the design of human-AI co-creation in writing.This paper explores the value, benefits, and concerns of generative AI-powered assistance in writing. The authors conducted a randomized human-subject experiment to understand people's attitudes and experiences with AI-assisted writing. The study found that participants were willing to forgo financial payments to receive AI assistance, especially when AI could provide direct content generation assistance and the task was highly creative. AI-powered assistance increased productivity and confidence in writing but also decreased accountability and diversity in writing. The results suggest that the perceived financial value of AI assistance varies with the type of assistance and the nature of the writing task. The study concludes by discussing the implications of these findings for the design of human-AI co-creation in writing.