Power Laptop in Car - Please Help

[spartan922]

I own a Dell D620 Latitude Laptop and I am trying to buy a power cable that will allow me to use it in the car. I have come across the following items so far:
http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=310-4804
http://www.pricegrabber.com/user_sales_getprod.php?masterid=33898244&lot_id=6450459#ship

I have no idea which of these is the best option. They seem very expensive...am I looking at the wrong items or all car chargers for laptops this expensive? I already own a power cord for home, is there a cable i can attach to that to power it in the car? Sorry if this seems like a stupid question but I don't want to make the wrong choice. Any input is greatly appreciated, thank you.

 

[The_Other_One]

Well for very little you can get a power inverter that converts a cigarette lighter plug into a standard 120v plug. You can get fairly powerful ones for about $40, or just little ones for next to nothing.