Footings & land cost are not included in my <$145/sqft 'guess'.Such a modular build concept would certainly alleviate a lot of the unknowns for a 'first time' project.Good luck...

Putting up 100k for flip deals in a heated market where deals are few and money is cheap, it seems like potentially a lot of risk for 8-10%, but i think that mostly stems from fear of the unknown.  

Closing costs: $10kPrincipal and Interest: $4200Taxes & Insurance: $200HOA: $700 (this will increase in a few years when the building undergoes pipe replacement, unknown how much but I’m estimating around $300).Electric & Internet: ~$200Total: $5300, likely $5600+ in a few years If/when I move out, I would likely be able to rent the unit for $3300-3500 or $3600-3700 if I rent by the room. 

This is to cover general daily business expenses and occupancy volatility.Rain day fund - this is for the unknown.

Though not completely off the table, a severe recession is unlikely.Based on the strong job data, stable weekly unemployment claims, and high household cash balances, there are no signs of a recession at this time.In the (unlikely) event of a severe recession, the Fed will cut rates, which helps to boost home prices.Severe Unknown UnknownsNo one predicted the impact of COVID until it was upon us.

So to know how it will compare against FHA is an unknown.

It became evident then the city was going to ******** their way through this process for an unknown amount of time. 

Do not make changes during the process unless something truely unknown happensWork constantly on communication skills.

Below are some baselines, but you'll want to dig in deeper to the unknowns so you can run your numbers Snow removal: $600-$900Gas & Electric: ask for records on the property in question Transit Occupancy Tax: 10-14% depending on market/jursidiction Management Fees: 8-25% depending on scope of services offeredPermitting: Varies per county, 2 states & 4 counties in the Tahoe BasinSewer & Water:  varies per county, ask for recordsTrash & recycle: varies per county, ask for recordsBear Box installation: If not present, required for most STR homes. $1400-$2500 depending on size.Im sure I am missing some but thats a start!

Hard for anyone to know what surprises will be uncovered which is why your budget and your schedule need to accommodate the unknown.