Right now, the market is so hot with low inventory, and properties in Sterling don't last long.  

Likewise, in NC there are some higher priced markets like Charlotte and Raleigh which look great but the Triad offered a reasonable entry point with (ordinarily) good inventory and a diverse and growing economy.

A lot of competition with not a lot of inventory in the area.

I would look for something that aligns more with my investment goals but the available multifamily inventory seems limited. 

Right now the cost of materials is at least 40% higher with low inventory.

This shop is owned by a small business that uses it to house inventory for their wholesale business.

Medium household income growing and pre-qualifications getting more common, the housing inventory is not able to keep up with the demand!

Good strategy, but somewhat unrealistic in the current market conditions in Cleveland (and likely in most of the country).The 75-100k price point is insanely competitive right now with both investors and first time homebuyers alike looking to take advantage of record low interest rates... on top of inventory being extremely low.  

Additionally, there's more inventory for duplexes than slightly larger multi families in IN.What are people's thoughts on this?

As @Courtney King mentioned, Texas market especially Houston and Dallas are very hot right now due to low interest rate, low inventory, high demand among other reasons.I will suggest you narrow down your options and take actions.