I doubt that he has actually betrayed the brotherhood, he has invested to much into it and he would know that he would be considered a loose end to be tied up and there would be no one willing to house him in any way, shape or form after such a massive betrayal.
The only thing I can think of that could be offered to Saboru would be something related to that Genjutsu Master, who in the past faced Hashirama and Madara. So it could be that Madara has something from him.
(Traductor)
Thanks for the chapter author san and keep up the good work, Saboru better be killed properly or you could make him a slave, Idk how but that will be a good idea.