You have to build your list first even if buyers are annoyed by you at first.
Step 1. You can find out what zip codes are hot buy doing a listserve trick to determine the better zip codes. (Your cost $0)
Step2. Then you buy a list of recent absentee home purchases for $6 from Fiverr per zip code (hopefully you found 1 or 2 in step 1). If you spend five minutes per property and do some reverse engineering you'll figure out if the property was bought as a rehab. (Your cost $24)
Step 3. Some of the lists have phone numbers all of them have addresses. You can send a post card to the buyer and ask them to look at your properties for sale as long as they sign up for your list. You can call them and ask if they are looking for more properties like the one they just purchased (You may need to skip trace the investor). (Your cost $150)
Step 4. Put out bandit signs in the target zip code(s). Two types
4.1. "We Buy Houses ..." (Your cost - $200) Put out 10 every week at different areas of town until you find a good fishing hole.
4.2 "Please buy my house by Dec 1st or the bank will win. Tel/Text XXX-XXX-XXXX, 3 Bedrooms 2.5 Bathrooms" (Your cost - $5)
Step 5. After two weeks you should have a real buyers list of 100 cash buyer. Join other investors wholesale lists and offer to co-wholesale their property for free. You'll ask the buyer to throw you some funds at closing or just keep gaining knowledge and growing your list. (Your cost $0 - You might make money)
Step 6. You now have a power house list of 1000 names of private money, hard money and rehabbers. You can do deals yourself and stop being an annoying new wholesaler. (Laugh all the way to the bank)