It seems you live in China- so I would assume it's easier for you to book locally at a more reasonable rate? For a first-time visitor that has little time to book locally (and maybe little familiarity with the area), this could be difficult.

Using your number, you're estimating that a fair rate is RMB1,000 or so? That does seem fair, as I had local contacts with drivers that quoted around RMB900 (some were even less, but not deemed very reliable). But, these cars would only have taken us to MuTianYu and back. They would not have been with us for 9 hours, and would not have had an English speaking driver. For me, that's no problem, but in the event my flight PVG-PEK was delayed and our friends already in Beijing used the car without me, that would have been an issue.

So for first-time visitors that don't speak the language and want to book remotely, I still recommend Hertz, even though I agree that cheaper alternatives exist. But, if you know drivers or companies in the RMB1,000 range that offer all of the above, share!