How to get a Rental Comp??

[Lawrence Cox III]

Hello, I have a property in south Texas. It is a vacant lot that the wife and I have thought about making part of our investment portfolio. It is in a small town that does not seem to have very many rental properties. There is not a whole lot of jobs in that particular town, but there is jobs in the surrounding area. I have talked to a realtor in the area, but have had no luck with getting a good answer if there is any demand for rental in the area. So we have been hesitant about developing the property. How could I go about finding out if it would be a good place to develop?  I know we all would like to bet on a sure thing,  but defiantly can't afford any finical set backs on developing this property thinking "if I build it, they will come" and no one shows up. I have wondered if I should look into Section 8 housing in that area and see if they have any demands for any rentals for that area. Any suggestions would be appreciated. I am new to this and would love to develop this into my retirement portfolio. Please let me know if any additional information is needed, and feel free to ask me questions. Thanks is advance for your help.