Good answers in the thread already. I just want to add one element: If you just 'throw it over the wall' and into the realm of open source, then it will almost 100% certainly fail completely as an open source project. Open-sourcing and then running away is the same as killing the project outright.
There are way more open source projects than there are volunteers. If you don't trust me on this, then go have a look at Sourceforge and Google Code notice the projects that have not had updates for 2-3 years.
For projects to succeed, they need careful stewardship, a friendly community to attract developers, and some 'hotness' in technology or elsewhere that can motivate and inspire developers.
a way I can make it OpenSource so people can contribute to the software and eventually when it's running as it should, sell it?
Yes, dual-licensing, as Steve Wilkinson pointed out. But this requires you to obtain the copyright (ownership) for all open source contributions via a contributor agreement. That raises the bar, and makes it harder to attract developers.
And additionally, if you open source just to 'feed' off the open source energy and then sell for profit, then expect your reputation to be permanently damaged. The open source community has its own set of values, and they're not always in internal agreement on them, but if they become united against an 'outsider' they can hit hard...