For example, places like Decatur and Hartselle—which are 25 and 35 miles southwest of Huntsville, respectively—could work well on your budget.

I live in a small poverty town in southwest New Mexico with storage units in high demand & all storage in town are rented/full. 

I have had great success with the southwest area of the Hilltop.

I can tell you hitting the $500 + monthly on seems very rare these days for now. even if guaranteed what is the likely hood it will continue once the lease is up.Right now we are "all in" on Southwest Fl.

My house is locate at a prime location in Sugar Land, TX, which is in the south-west part of Houston, and one of the safest cities in US.

Looks like you would prefer something in South to Southwest Houston. 

any good recommendation for good property management company in South West San Antonio for managing upto 20 units multifamily

Granted, North side appreciates better, but South and Southwest side cash flow, and are appreciating more as they get discovered by people priced out of North side. 

Mostly Southwest uses Love Field, the smaller older airport....so don't go there looking to fly to Sydney.Dallas has to be Real Estate Meetup Central....seems like 3-4 a week depending on your focus.Two I really like are on Thursday nights in Dallas NTAREI and Saturday mornings in Fort Worth DFW Real Estate Investor Club. 

I personally invest in short-term rentals in southwest Michigan because I live in the Midwest, it is an area that I frequently visit, we find our returns are strong, and they have approval for short-term rentals .