Yea, I've called probably 8 or 10 4x4 shops, a lot of them throw the old springs in a metal recycling bin that gets picked up by a company and taken away.
I found a set in Virginia, but they will be $215 after shipping!!! I don't think thats a good price for springs with 105k miles on them.
I have an F250 and have researched the Dana 60 swap quite a bit, and I don't mind the way the truck rides right now, plus the price of a decent Dana 60 is more than a 4" lift and shocks, and by the time your done it may even be double.