I have a new payment system idea and I need a web developer. Before we begin with, I will always like an NDA agreement, I will also like to discuss the SDLC stage, know my rough cost from the beginning to the end and also, I will like to work with someone that is interested in new innovatiosns and can also contribute his/her own knowlege into the whole idea. 

We can always be partner, it depends on how interested the developer is.