The city wants it condemned and I'd base it on land and demo. costs.

I just got my demo permit..

I have used Al Nutter, his company is Nutter Busters Demo, before.

I also wish that I could swing a sledge hammer and haul demo to the dumpster as swiftly as my contractor.  

And doing some or all of the demo yourself is a great idea. 

I did a demo with Batch Lead Stacker and I like they are very responsive, engaged, they host webinars several times a week, and have a FB group.

It was a 1500 sq ft 3 level home with a detached garage and apartment unit above the garage.It was a massive trash out and demo filling 2 40 yard dumpsters and a 20 yard.  

Demo (remove sink, pulls, stove, frig): $0 - 3 hoursCountertop Transformations (small kit): $150 - 10 hoursL-brackets, gas valve, misc.: $40 - 3 hoursGel poly-stain: $15 - 20 hours (estimate with sanding, cleaning, 2 coats staining)Pulls (3-10 packs): $35 - 1 hourSink & Faucet: It was given to us but original cost of $200 - 5 hoursPendant light (can light conversion): $25 - 15 minUsed stove and refrigerator (craigslist): $600 - 4 hours (pickup and placement)Vinyl Flooring: $150 + $300 install

I had a great contractor and we worked almost like partners.I learned a lot from him and did a lot of the demo and some repairs under his supervision.

Assuming I find a lender (which I'd do before making an offer), I'd use a conventional mortgage to demo the house and build a new house.