Building a 4 Unit Studio Apartment?

[Kenneth W. Lee]

Hello everyone. My wife and I have bought some empty land in our town and going back and forth on what to do with it. The numbers seem to be in favor of building 4 Studio Units. Talking about 500 Sq Ft per unit. Rent would be $600 per month with the tenant paying utilities. So $2,400 per month / $28,800 per year with all units rented would still have to count for Insurance and Taxes. Doing the math I would be about $75,000 all in. But assuming more like $100,000 all said and done because I know nothing ever really stays under budget. These numbers are me doing all the work and maybe hiring out drywall finishing because that is one thing I could never learn. 

Return on investment numbers look good but at the same time, I feel like a couple of years to get my money back is such a long time to wait to get all my cash back, unless I get a construction loan to build it and then refinance it once I get it fully rented. Assuming a 10% cap rate  would be able to pull out a loan for $230,000  ish which would let me get my money back plus enough to get 4 more units built. 

So I guess long story short please tell me if these numbers make sense and if would this be something you would or wouldn't do. Why or why not? 

Never done apartments before only have done a couple of houses so I apologize if I sound like a rookie because I am!