At alfa aesar it costs $309 for 5g, 1111 for 25g at the moment. There are quite a few papers on it, if you search hexachloroiridate in google scholar, for example, you find a fair amount. It is a common iridium precursor, although I use IrCl4 myself.
If you have specific questions just ask. I collected quite a few papers on iridium in the last few years, so maybe I have suitable references lying around.