Sounds about right for an estimate - lots of labor involved to straighten a dent out on a door - assuming this is past what a PDR system can do.
Since the car is so new - should be much easier to match the paint of the door - as the rest of the finish will not be faded or damaged by environmental conditions. That said - metallic paints are not 100% easy to match - even with the exact same paint, how the paint is applied will affect the final finish.
That said, a competent shop should be able to match the finish enough to look like a near factory job. Assuming that shop will use a multi-stage paint (separate clear coat and color coat) and all prep work - you could be looking at $250-$750 for the paint job. Single stage paints can be cheaper, but less likely to match the original finish. If you do the prep yourself (strip the door panel, clean it, etc.) could save yourself even more. Check around - look at some example work by the shop - not all shops can effectively handle all types of paint. Some have intimate knowledge with how the metal prep and primer color and chemistry can affect the final finish.