I can give two answers to the how old question.
The short answer is between 10,000 BC and 2500 BC because that's when the Neolithic period was in the area making stone arrowheads.
The long answer is that I figure they aren't the very earliest examples from the Neolithic period, but most of Central Asia and China had switched to bronze arrowheads by 2500 BC or even earlier. So I'll guess 8,500 to 2,500 BC, which lines up with most of the African points you see on eBay and at shows.