As I recall, the Astrodome cost <$40 million to build. I suppose it will cost more to raze it.
I really have fond memories of that stadium, especially the comfort of watching baseball in Houston in 71 degree weather, beer in hand in a seat that set me back $2.50. (1966)
The Astrodome was somewhat of an improvement over Colt .45 Stadium, was it not?
I can't say I missed the mosquitos...