With Just the split foyer and garage underneath I'm looking at roughly 160k all in (these figures include what I paid for lot). 

Soft costs including designand engineering plans ($1 sqft), plot plan($600 deal from connection ) and soil test for septic ($500 to plumber for excavation and 200 for city).

The good part is there is hardwood underneath.

We have lots of 1920's homes and they were wood frame and stucco but overtime and termites it can be lots of structural damage underneath. 

Cost for the property associated with developing the land before construction will vary based on grading, sewer, electrical, roads, surveying depending on the location of the land, soil testing, etc...

Then, you remove all of the damaged materials, and depending on what happened underneath, if nothing, then you're done.

In-ground tanks can leak for years and years and no one notices until lots of oil has permeated the soil.

That newer asphalt, or when it is resealed or newly striped, looks pretty sharp (but then you have some costs and maintenance), but I am not sure the attractive lot would bring much more in rent nor would gravel drive off good tenants.Finally, I shovel snow with the body sled type shovels and it would knock me out without a smooth surface underneath like asphalt or cement, so with gravel maybe check how that would work with your snow removal system (be it shovel, snowblower, or plow truck)...probably gravel best fit for plow truck...Best of luck

We even got a bonus surprise when we pulled the carpet and discovered some awesome 60's, rock print, green vinyl underneath. 

AC is barely working,There were some moisture issues underneath the tub from the upstairs bathroom.