AFAIK any time gov’t takes property/land from private owners under eminent domain, the owners are always compensated fair market value.
I wasn't interested in selling so I didn't pay much attention to the details but I seem to remember hearing that the state was offering 2 times the FMV.
I don't think that this is the standard practice in regular eminent domain cases but this was different in that the state was just trying to get us to leave our property and had no plans to use the land for the public good.
I realize that the Federal Government has virtually unlimited funds, but buying all of the private land along the US/Mexico boarder could probably get pretty pricey pretty fast.