Sounds like an interesting assignment.
About a year ago, someone hired me to write a 90 page ebook.. and expected it within a day. When I told him it wasn't physically possible, he started using all these slurs to pressure me into finishing it as soon as possible.
After postponing the delivery date for a whole month, I finished, but the buyer did a chargeback for the payment (basically a false report accusing me of scamming); the few hundred bucks I was expecting was cancelled/he got the thing for free.
The lesson? NEVER sell products/services without a trusted middleman. No matter what, don't take ANY risks with big payments.
