There is significantly greater inventory for SFH, a duplex will be tough to realize the same opportunity unless it is vacant.  

Inventory is tight right now to say the least, but will hopefully loosen up over the winter.

There is not enough inventory and the margins are just too thin in SD for my partners and I to invest. 

Generally my understanding these days is that inventory is low country-wide, which is driving prices up.  

This also depends on the inventory and where you feel comfortable building a team.

Property you purchase with the intent of resale is considered to be inventory by the IRS and you cannot 1031. 

Only few brave souls will want to sell their house because of the uncertain covid times, which keeps the inventory low despite the high demand.

@Curt Mason we've involved in both Indianapolis and Kansas City and from my experience, COVID has had little to no effect on the markets, other than inventory is becoming slim due to the lack of foreclosures.

I am wanting to get build a new construction home on it to sell as inventory in this area is very low and has been for some time.

So 90k into it and with the increasing prices in the area from the low inventory and low interest rates attracting lots of buyers, the house has gone from market value of 181k-209k all the way from 209k-219k.