MF is a big beast and principles always look for investors- this will be expedited learning and you’ll earn too.Even if one has lot of money (million+) to invest, better to invest in multiple properties to help with diversification.Value add really helps to multiply money and in case of MF you can have partners manage it for you.. say you can onboard 2-3 partners with less cash contribution but commitment to manage reno and other things.. 

In a few years, you could be making bank if you can increase the rents because when you increase the rents you make hundreds of thousands of dollars in equity because rent increases automatically increases the value of the property.One way to get a rule of thumb value is to ask a real estate investor what the Gross Multiplier is for apartment buildings in the area.

Now multiply the number if piers by $250.  29x250 = $7,250.Now add $200 for permit & $400 for Engineer's letter (yes, both of these are required by the City).  200+400 = $600Total foundation price = $7,850.  

Then multiply this monthly number by the total sales price.- Insurance: Not sure.

With real estate, you get to multiply your buying potential by 4 - meaning that the bank only requires you to put 25% down.  

I calculated the annualized return using the equation for simple interest(multiplied 5.6% by 52/3,) your calculation considered the interest to be compounded.

I want to generate multiply streams of income from the land and the extra building.

If you want to take it a step further, you can take that average dollars per sqft(minus any inaccurate comps) and multiply it by the sqft of the home you're interested in and this will give you a good base price.

@Candice Brown multiply your numbers by 20 and you will see some results.

I am a big fan of the rent multiplier i.e. 1% per month etc.