That Actron is cheap, but it is NOT a DRBIII. The actual DRBIII is really not officially for sale, but if you can get one if you look hard enough. However, I was told they are about $2500 AND you have to have the main computer the dealers have to link up and download software for your car. Without that the DRBIII doesn't do much. I think the DRBIII is now being upgraded to a DRBVI, don't know anything about that.
Chrysler's computers are soooooo proprietary and closed. It's hard to get a scanner that will do anymore than interpret the simple emissions codes, and it's difficult to have performance chips like our GM and Ford counterparts.
I've got the Service Manual and all the diagnostic manuals for my 99 300m. The diagnostic manuals are almost worthless, since they basically tell you to get the DRBIII and follow the prompts to troubleshoot this and that. Also, for example, to properly service the 42LE tranny and adjust shift points, quick relearn mode, etc requires the DRBIII. This example and many others, pretty much requires a trip to the dealer for advanced troubleshooting and repair.
That is why I was looking for a DRB3. Book is mostly how to step through one to find the electronics problem more than anything. Still has some great diagrams that Haynes needs to incorporate or even Chilton if they ever manage to put on together.