I charge a flat rate, typically breaking deliverables down into 1,000-3,000 word chunks and charging around $500 per chunk. However, but I give discounts for the following:
10% off for nonprofits and small companies making less than $100,000 a year
10% off for "serious" game projects focused on education, increasing representation, or other benefits larger than just entertainment
10% off for clients buying at least 6 of these "chunks"
And you can totally combine both discounts if you qualify for them
Once we've had a chance to discuss what you'd like me to do, I'll give you an estimate within a few days outlining what the cost will be and when to expect it by.