You are looking for a long lens camera, with 10X optical zoom.

The lowest price for this type of camera is the

Kodak S1-IS
Konica Minolta Z2
Panasonic DMC-FZ3

Taking pictures at dusk can be done with any of the cameras.......BUT......you will have to use the manual controls on the cameras to select a slow shutter speed. This means you will need to set the camera on a tripod or something solid.

Most digital cameras let you select how much noise they make. They can be totally silent...not even a shutter click.

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