You will likely get scammed my dude. There is a sentiment here amongst the crowd of developers that if you don't know how to build it - you can't have it.
What has worked for me over the years is empowering these developers - don't buy the source buy the skills of the developer. Provide them with a design/plan and a payment structure that adds to their life; and from this I have been a part of many servers.
Give it a try.