It's a complete new unit - not just the glass.
Now... the fog lamps have been revised from the original ones which came out on the 2004 models. I have a 2005 and it came with the original fog lamps - I think the chrome cover for the bulb kept falling off so they did a redesign at some point.
Do a search, somebody posted pics of the old and new fog lamps - if you don't know which ones you have, you would be wise to find this thread.
The new lamps look a lot different to the old ones - so you may have to buy both LH & RH.
Mine were replaced under an insurance claim about 12 months ago - about $85 each.
Hope this helps.