It would be a good deal $$-wise, but here are a couple of generic things to check out and consider. If you haven't already done so, try to find out if the oil was changed at good intervals (which depends on syn or non-syn oil being used). It wouldn't be unusual for an elderly person to just "forget" about something like that, and IMO you would be looking at big problems buying any vehicle which has gone 17K without an oil change .
The other thing to ask about and consider is Granny's driving pattern. Modern vehicles are designed based on the idea that they will come up to full operating temp, and be running there for at least a while. This gets much of the gunk cleaned/burned out of the systems. And it also helps when the car is "punched" occasionally, giving it an extra clean-out. So, if she basically spent the last 5 years making 2 minute trips to the store at 25 mph, then you may be looking at a vehicle with the stage set for some problems down the road. But OTOH, with only 6K in, you're way ahead and probably would still come out in the black for the life of the vehicle. Good luck with it!