Thanks for the feedback everyone. A friend of mine is currently having his 15 000 point 40k army being painted by someone, and the rate he's quoted is great so I think I found my painter.
I might wait and see what your friend's finished product looks like first. There are some shady characters out there that have heavily photoshopped examples of their paintjobs on their websites, which don't accurately portray what their real work is like.
Plus, if the studio is painting 15,000 points of models at the moment, it MAY be some time before they have time to get to yours.
Just like any contractor / client relationship, buyer beware. However, I would compare them with Chad... I know from personal experience that he's super professional and reliable, and a pretty damn good painter as well. You get what you pay for sometimes...