19k shutter count for a Nikon D3100?

Is 19k shutter count for a Nikon D3100 considered high?

For a used one?

I've had a Canon 600D and am up to 17000 over nearly 2 years of intermittent photography.

Shutters are rated to typically over 100000 actuations, so perhaps 10 years of use on a casual basis. You're likely to get a new camera before the shutter dies, unless you're really going to hammer it.