Lead? Asbestos? Other toxins?

500k? Is that 5 story factory? Contaminated land? Are you building house in the exactly same spot as the old one and need the foundation removed keeping undisturbed soil? Debris disposal is pricey?

Here 10k would demo 1 story, 20k two story, the dozer is 1k/day rental. Fire department will burn down a house for free. Oh, yeah if you think that a "BIG company" just open the wallet and pay $0.5mil you re naive.

Can't even begin to speculate without significantly more information.

There is a tiny cottage with an old wallboard product that contains about 10% asbestos. But all of them said it's not an issue in my county, they basically have to separate the waste and that's it. A 3000 square foot block house. Three barns and 3 run in shed type buildings, which according to the winning bidder have little actual material. Some old wood fencing. They're just burying most of the old house's foundation. And all bids contemplated crushing the block from house and barns and leaving it on site. No pricey remediation or anything, just knock it all down.

No, I don't really think anyone would pay those kinds of prices without blinking. I'm really at a loss. The one story wood frame tear down that preceded our old house cost about $15,000, I thought that was expensive at the time.

Ok, this is a bit of the scope. Basements? Foundation removals?

We have reviewed the scope. I'm a lawyer, husband is a architect. They're all basically the same. The silt fence (may not even be required, we're not on any stream and the buildings are far from neighboring properties) isn't included in the low bid but I don't think it will cost as much as the delta with the next lowest bid. :-)

There is a basement on the house, it'll just get penetrated/broken up and buried. There is a lot of concrete in the dairy barn foundations and floors. There's a huge concrete silo but we're leaving that, will figure out something fun to do with it.

The low bidder is based further out in the country than we are, but is still a reputable area contractor. Maybe he's just better aware of how little it will take to demo the agricultural outbuildings?

Go with the lowest bidder and I will put up the silt fence for $100,000.

I'll do it myself and I won't have to pay you. :-)

Another golden opportunity passes me by.