Feasibility of building a master list of multifamily properties in your area?

[Nick B.]

I'm starting to hone in on my first multifamily property! My priorities right now are determining an appropriate market rent for 4plex units. I'd like to build a list of all properties in my area (pop 350,000+) to have the best representative list and populate rent rates where I can find available. This way I'll also catch properties off the market. Has anyone done this before?