We're giving them about $90k down but after he sent the paperwork to the attorney he has cold feet and wants to back out of selling.

Does anyone have any advice for how make quick contact with leads or how to find/build a list to make cold calls?

If you are just starting you might be looking at outbound (cold outreach) marketing instead of inbound because of the cost.

Cold called this property owner who wants $150K for this 2 bedroom, 1 bathroom 928 square foot home. 

Normally, my team handles cold calling and texting, but recently, we started using an AI-powered texting solution from a startup called Adforce, and the results have exceeded our expectations.In just the first month, we closed two deals that gave us a positive return on investment, effectively covering the cost of the service for the entire year.

I've already done some small time cold call mailers to some local multifamily homeowners in my area.

I cold called the seller and asked How did you finance this deal?

I hired roichamps dot com to do cold calling for me.

You can cold call or hire people to marketing for you. 

Prospecting is usually the best and most cost-effective way to generate conversations with potential sellers, plain old cold calling.