If it has cracks and holes in it "something" must have happened to it. Claim it on your homeowners insurance!

The vinyl siding can be replaced piece by piece. The problem is that on a 13 year old home the color will have faded and you will never get a good match to the existing color. If it's white it might match okay.
I would look in the yellow pages and find someone that does siding and ask if they would look at it for a repair and give you an estimate/advice.
Most of the vinyl siding that I've seen might be from a major manufacturer, but is of a lesser quality than you'd find on a typical home. Sometimes it's referred to as "builder's grade". It might be the same material, but it's about 25% thinner and costs less. Holding the two grades side by side you can't tell the difference.
As Nessie said...something had to be hitting against the siding to cause the damage. Holes don't just appear by themselves. Most siding is guaranteed for about 50 years so I would not be afraid to use it as long as there aren't kids throwing things against it.

There are reasons your siding has cracks and holes in it. But they don't happen by themselves. Are you the original owner of the home? Cracks come from something hitting the siding. And holes come from drills, or nails, or screws.
People sometimes want to hang decorations or flags from the home and just nail into the siding. The doesn't allow the siding to expand and contract in the heat and cold, and as a result, the siding must do something, so it cracks or bows. The WORST thing you can do is attach something to the siding using a nail or screw.

there is a HUGE difference between builders grade and mid grade on many items... siding would happen to be one of them.