From what I understand the goal you set is totally up to you. For a game project I would take the time you need to sit down and do a real budget. Maybe connect any for-hire artist and specialist and get soft-contracts and a good idea of a price point for services in their field. You might want to think about ask for enough money for a conservative build of the game but also over ask as you might fail and because fees for things can shift. At the heart kickstarter(like the name suggest) is a get-you-started point. If you raise $100,000 USD (but need $5000,000) even for a big game project, you should be able to create a build with it that you can shop to publishers. As for getting the word out and keeping the the word going - for this I can think of no reason why you should have a professional publicist handling. If after all a lot of you fund for the game are going to come from kickstarter then maybe raise so in-home money for a mouth-piece before posting a campaign is the best idea.

I will spend some time looking at services that do marketing for KS campaigns and see if I can get some links posted and maybe some price quotes.