I did some research.
Here is what you can expect to find in the Campo del Cielo specimen:
These meteorites are from a large event and are not particularly rare. They fetch forty to fifty cents per gram in a fair market, though you'll find them far more expensive on ebay.
The Sikhote-Alin meteorite was a witnessed fall which increases its value (among collectors, anyway). It was also the largest meteorite impact event in recorded history. There are two types: Individuals which landed intact during the event and explosive fragments from parts that detonated near the ground under heat stress. The one offered is an 'individual' and is more valuable as a result. Not many are sliced due to their value. Those that are, vary considerably in their crystalline patterns when etched. These are prized specimens and command $2 to $3 per gram.
I'd accept $250 for the Campo del Cielo ($0.38 per gram)
and $125 for the Sikhote-Alin (1.52 per gram)
As I said, I'll entertain all offers.