Okay, first off the rescue info, if you find a doberman rescue, that would be the best way to go. Rescues are different from shelters for the most part. The dogs have been thoroughly tested with many different issues, kids, food aggression, other dogs, cats etc. Also many of them are in foster homes waiting for their forever home, plus the rescuers and the foster parents know the dog inside and out. So they are housebroken and fairly obedient. Then especially b/c you work, you could find an already adult dog that is housebroken. (big plus!) Here link to the DPCA rescue site....
http://www.dpcacope.org/ it's worth checking out at least. We have a few great rescued dobe owners on this site that I'm sure would love to tell you about their dogs!
I'm not trying to convince you either way, they are just facts and options out there for you. Here is also a link to the Doberman Pinscher Club of America, you can get some great info about the breed from it also...
http://www.dpca.org/
Dobermans are great dogs, but they do require an amount of work, they love to be with their owners. There are a lot of shady breeders out there with the dobies.... so it is imperative to stay away from them.... That is the reason for a lot of the sky high prices you are finding. Really check out the "buying a doberman pinscher guideline" listed in our breeding section to help you weed out the bad from the good.
Dobies aren't an easy dog to own, they are highly intelligent and love to be doing something. They require exercise, they do shed, (although with a shepard already, it's not anything you haven't already seen) they love to be challenged and work, it is important to socialize them early on, and regularally.