My State Farm quote (who I have my personal stuff with too) came in at the same premium amount and will insure at 100% of replacement/rebuild.

I was planning to rebuild in the same spot.

The other factor making the 3 family rate out higher is that because of the extra Kitchen and bathroom(s) the rebuilding cost (Replacement Cost) for the building will be higher for the same square footage. 

Existing house of a property we are considering needs so much work I think it would be more beneficial to completely demo and rebuild. 

RCV is the way to go, but be careful it may not cover all you think it does - typically RCV will only pay out if you actually have enough coverage for total rebuild and actually intend to rebuild following a catastrophic covered loss.

I often hear people say they pick ACV over RCV insurance when the cost to rebuild would be more than the market value.

I found someone else for less than half that and they used them. 2) A plumber charged me $260 to unclog the kitchen sink, the tub, and rebuild the shower faucet.

Even if you have to demo and rebuild the shed, it would be cost effective.

In an A community the land value is high enough that if the subject property were to burn down, it would make sense to rebuild a bigger and better property.In a B community the land value should be substantial enough to rebuild the same property, in square footage and included features.In a C community the land does not support rebuilding, and the lot will remain vacant for years to come.

My last project is a full teardown and rebuild of a SFH in DC which I just finished this month.