Honestly, I don't have experience with the betting service, however that shouldn't be a concern.
I would call it a day, and research on betfair for whatever is there to research for, related to the project. - I wouldn't ask for money for my research.
Anyways, I do have a good experience with c#. I have added a picture of my first completed project, it's in my portfolio if you're interested.
I just started with this website, trying to figure out how things work here, still learning from employers, - though I'm pretty confident I can do your project.
Message me for more information.