Hiring a coach, GTD or otherwise, often does cost a fair amount of money.
Based on being new and setting everything up, unless you have lots of money, I would suggest its too early to hire a coach. Instead, read the forum, post, look at old webinars and begin setting up a system. Realize, unless you are very lucky and intuitive you will need to tweak your system as time goes on...and that's ok. Think of it as a long-term process.
I've found great value by sharing and listening to others. I hope it works for you too.