I'm not an artist but I'm a writer. Here are the prices for my stories:

A short story (3 to 4 pages) go for $20 USD
A short story (10 to 16 pages) go for $50 USD
A Screenplay for a short film (30 to 45 pages) go for $100 USD
A Screenplay for a feature length film (90 to 120 plus pages) go for $150 to $300 USD

A hundred page story will be $700

Time wait (depending on the circumstances) are:

Short Story- 1 to 2 weeks
Short Story II- 2 to 3 weeks
Screenplay- 3 months
Screenplay II- 5 months (these things are not easy to write)

Additions:
Poetry- $2 USD (3 day waiting period)
Yiff Story (a story that is nothing about sex 2 to 3 pages)- $15
A medium size short story (5 to 10 pages)- $$30

If I go over on page count than what you request, you only owe me for what you commissioned me for.

Ahatu
PS: Example of my work will be posted soon!!!!!