I believe that active land sales in the area are probably the most important but other factors to consider can be market size in the area you are looking at, cost basis that you would like to start at if that's a factor for you, and the land its self. If I remember correctly I think one of the modules that was provided to us, it spoke about making sure that the land itself looked level enough to build on if its in a residential area, not prone to flooding, etc. Im sure that I missed some other factors, but I hope this helps! Best of luck!