I would pay for the private one, sure source code allows for a whole lot of bypassers, but if every bypasser is public, then it'll be quickly detected. As well as if it was just public.
On the other hand, I hope you choose whats better for you. Public is gonna give you a lot of work, having to make it undetected every time it becomes detected (which will be often), whereas private is gonna be slack-ish and might give you little to no work at all, if work is what you seek.