Building a duplex or small home for rental?

[Jimmy Smits]

I would like to build a duplex but then cost is higher than a small home. The goal is to buy land...build one or the other...every couple years or so pull out the equity and build another on the same land. Eventually have a small community. 

Building costs are high right now. I could build a small home for about 80k. A duplex will likely be 150k. 

I wanna spend as less as I can on this build because I want to invest more in the stock market while its beat. In 3 to 5 years anything you buy now should at least be worth double. You wont see that return in real estate. 

I want to build income on real estate.

Any help or advice anyone can give me?

I likely will see a CFP. it may be possible to finance the build instead of pay cash.

Never been a real estate investor. Always leaned stock market. 

But I need a new place to live so figured a duplex would be the best. 

Thoughts??