The owner would cover the cost during vacancies and within the first week or so of a new tenancy if needed as a courtesy.

Low Repair Costs: With only $2,500 needed for repairs, the investment required minimal additional funds.

The buyer agreed to a purchase price and all fees/costs.

The leverage and arbitrage when used to its full potential far exceed the costs.

Many clients from Canada also boast that pricier neighborhoods in the U.S. for example Miami, are only a fraction of the cost of properties in Canada, so their ROI is much higher. 

my father has been investing in detroit for 22 years over 100 different properties i am not sure which is the better choice but we always have the tenants fill out an affidavitwater bills in detroit can come in extremely high at times and if the tenant decides to skip out on paying rent and bills, it can cost you thousands if it is under your name and not theirs.

It's in a city (outside the USA in Mexico) that has seen major growth the last 3-5 years and has great prospects to continue growing thanks to nearshoring and high cost of living across the border in the USA.I spoke to an architect and it looks like a 4-unit building can be built on there.

How much is the average cost for the upgrade? 

Cost $800,000.  

It means you could deduct 100% of the cost against this years revenue.