Good ghostwriters can be very expensive.
The way to learn to write is by writing. He's just going to have to buckle down and write that book, and another, and another, and learn along the way - books about writing, Brandon Sanderson's creative writing lectures on YouTube, Holly Lisle's and K.M. Weiland's courses and articles, to name a few resources. Or he could join National Novel Writing Month, participate in their forums and events. When he has a completed novel, he might want to look into hiring a developmental editor to help him work out the major story problems. Expensive, but cheaper than a decent ghostwriter would be, and he'll learn the skills to help him write his next book. But hiring someone to write the book for him won't teach him anything. Yeah, the first draft of the first novel will probably suck. That's just the nature of the beast. You learn to write by writing; there aren't any shortcuts. It's hard and it's work, but if he really wants to write this story, it's worth it.
