$180 sheesh did you buy the truck from them? Did they throw the second one out? I wonder why so many used Ex only come with one key, you get two from the factory.
You can also get the key and fob off fleabay. I only paid $10 for the fob, and $10 for an uncut key with transponder.
For '04 you have PATSII keys with a transponder that is coded into the PCM. If you buy the above key and take it to a hardware store and have them cut it. It will unlock the door, but will not start. NOW call the dealer saying you have the key and you only need to Program the one old key and new key into the PCM. That has varied from $45 to $100 yes and its only 10min of work if that. What they do is hook the PCM up to WGS and add the key. Some have said some locksmiths also have a computer that does the same thing.
Found this too, they give you both for $20: 2003 2004 2005 03 04 FORD EXPLORER KEY KEYLESS REMOTE
Some have said this all-in-one works to for $50: FORD FUSION,FIVE HUNDRED,TAURUS UNCUT REMOTE KEY 06-08
If you have two keys you can put the PCM in add mode and do it yourself.