Building a triplex or quadplex good idea ?

[Data Brezack]

I've been looking for investment opportunities in the RTP area. Single families and townhouses are much to high for the 2k/mo rent they command and triplexes or bigger can't be found for under 600k for a decent piece of property. There are several properties I have my eye on that could easily fit 4-5x1300 sqft townhouse or apartment style places and are zoned to allow this.

The math so far is pointing that I could finish a quad for ~800k and easily net $4200/mo (rent on 3) then live in the last one.

I was wondering if anyone has anymore knowledge they can share on the matter. Its very odd that no one has really build anything bigger than a duplex in RTP since the 80s. Also if anyone knows any builders or general building rates in the area please let me know, google is failing me.

The other option is picking up student 4 bedroom apartments by the campus for 200k each and deal with 3-4 leases per apartment (Up to 8/year) trying to net 1400/mo. The profit for investment is good but I also wouldn't be able to live in a college dorm again haha.