What should I do with this Vacant List?

[Felix Wisniewski]

Hey BP. So I have a list of 155 vacant properties that I found myself from "driving for dollars". I have already went to the city and got the home owners names for who owns them. Out of that 155 only 50 or so came back with updated addresses of where they moved to and currently live. I'm on a limited budget so I was thinking mailing to those 50 or so & that would fit my budget and cold calling the rest as well as leaving door notes saying I wanna buy their house. Any response and critique to my strategy would be awesome. Thank you -Felix Wisniewski