here's maybe a more cost effective way to drive for dollars. Take a different route every time you go to work or run errands and drive down three streets. You still have to drive from home to work, the supermarket etc and vice versa. Except your combining looking for property as part of your trip. You can use google map to get a feel for the area before you drive through it...ie.e is there nice houses or are they not so nice. Google maps street view will be behind at least 6 months or much longer. So a house that has been vacant for 3 months may have a car in the drive way outside decor that was a captured a year ago. Again using Google maps is to give you a rough idea of the area to plan.
A couple of other free to low cost ideas.
Contact landlords and FSBO from Craigslist and other local classified sites.
I found at my local dollar store a window marker. You can write on the back window "I buy houses 555-1234. Just make sure you're not blocking your view and your not violating any local laws.
Put flyers around town on annoucement boards at supermarkets, laundrymats ecs. Black and white copies are about .05 and color is around .10- .20. Depending where you get copies made.
You can get business cards from vista print from free (plus shipping) to $10 plus shipping. Those you can leave few at dry cleaners, auto repair shops, hair salons etc.
With the exception of contacting FSBO And for rents, when you're doing free to low budget marketing it's mostly letting people know you're out there and what you do and essentially waiting for the phone to ring. Direct marketing to the home owner is going to get you a response much faster.
If you're starting out stick with 3 lead generating strategies for easier execution management, and financing.