Using \$ in pfgplots?

%%FOLLOWING CODE GIVES A TeX capicity exceeded, sorry [input stack size=5000] Error
\begin{figure}[h]
\centering
\caption{Sales in Billions(USD)
\begin{tikzpicture}
\begin{axis}[xlabel=Year,grid=major,xmode=normal,ymode=normal]
\addplot coordinates{
(2005,\$6.14)
(2006,\$10.6)
(2007,\$16.60)
(2008,\$21.80)
(2009,\$23.65)
(2010,\$29.32)
};
\end{axis}
\end{tikzpicture}
\end{figure}
%WHEN I REMOVE \$ within {axis} everything compiles fine,
%also how do i get rid of the commas if I'm using a year on the plots?