A lot of the same cost drivers as the Lower Rio Grande Valley. The private ownership of the land, the International Treaty governing construction which could impact floodwaters, the additional land left in the floodplain when you need to build the barrier on levees, and the shifting path/erosion of the river. As we continue upriver, hurricanes become less of a threat though.
Nonetheless, I think that we will see something like a 20% lower actual cost vs. what they have budgeted. We likely still face the need for a good bit of $20 million per mile barrier in Texas, beyond this year's projects.
"Many bad things have happened near Nogales."
Nogales got some of the earliest bollard barrier, before the Obama Administration, because of that. President Trump's Military deployment to the border has included adding concertina there, which significantly hardens them to ladder and rope attacks.
Nogales:
Mayor of Nogales is raising nine kinds of hell over that razor wire. LOL!
the escapes we had with concertina were with double thick blankets (old wool Navy style) thrown over the top. Were favored the inward (Towards Mexico) curved fence and none of our staff or inmates could get over it.
https://duckduckgo.com/?q=curved+prison+fences&t=osx&iar=images&iax=images&ia=images