Nature shots are a favorite for the professional and amateur alike. When taking pictures of little doggie or kitty, the home enthusiast can come up with some nice shots using some very fine consumer cameras available today. Most folks will simply not have the proper lighting equipment, lenses, backdrops, props and other necessities to produce the best shot possible. But, many people won't care either. The 'simple' camera I'm holding in the shot on the beach to the left cost about $5000 dollars including lens and body. The modest bag of equipment waiting for me on the beach contains another $4000 worth of lenses and more equipment with additional memory cards, flashes, and then there's the nice tripod and so on. For many photographers, this is only the tip of the iceberg. There's no reason the average person will ever have this kind of equipment laying around the house. This is one of the reasons you should think of a professional photographer when you need only the very best images.
The picture of me on the beach was shot with a very nice $400 consumer camera. Nice for simple vacation shots! If this was a wedding or party on the beach, you would probably begin to think about using something other than the camera you got for your birthday? It depends a lot on what the event is all about. Lifetime events are where you might want to rely on a professional instead of the nephew with a nice camera and a computer.
The professional takes not only the very best tools with them to any photo shoot, but also takes along years of experience. This is what separates the casual photographer from the pro. Like all things in life, a true professional is putting his or her reputation on the line to give you the best result possible. If you are smart enough to hire a pro for any work, you can sit back and be assured that the right shots are taken at the right time. You can then think of other nice things , like what's going on at your event! The simple peace of mind is worth the price.