MacKenzie, Binder, and Beloff all admitted to getting money from Serbs.
Which is, in all likelihood, the truth!
MacKenzie, Beloff and Binder were all in the film, "Yugoslavia, an Avoidable War", based on Beloff's book of the same name. All of them -- McKenzie, Beloff and Binder -- were verbalizing their previously stated positions on the break-up of Yugoslavia for a commercial film. The director & producer was George Bogdanich, an American of Serb descent. So, yes, if you were to stretch the truth and warp it, you could say that they were "paid by Serbs" -- knowing full well that such a statement was deceptive and devious.
But there is a big difference between "paid by (American) Serbs" to state positions that they already repeatedly stated elsewhere -- verses being "bought by Serbia". There is absolutely no evidence of the latter.
MacKenzie, Binder and Beloff were not ever "media creations of Serbia" -- all had high-visibility careers with ample evidence that they held these balanced positions on the Yugoslav break-up long before any American of Serb descent paid their expenses to speak somewhere & be heard, or paid them to be in a commercial film (for which only a wealthy idiot would do for free).
Besides which, if you are honest, you know that none of these people could ever have been paid enough by American Serbs to endure the attacks on their reputations and character that they have suffered because of their refusal to toe the "anti-Serb party line". The only reason anyone would suffer the way that all of them have, endure it and keep pushing forward is because what they are saying is the truth!