Timing Chain Estimate on 2000 Ford Expedition

I am trying to locate an estiamte for having the timing belt changed and I can not find it in the repair pal any suggestions

Asked by for the 2000 Ford Expedition
There is no timing belt in your truck, it has a chain and no regular maintenance for the chain, no replacement necessary, unless there is an internal problem.
Why do you think it needs to be replaced?

i know someone who has 280,000 miles on their truck and want to replace it.