1. Meet investors in the area(s) you plan to invest. Attend every REI event available within a hour or two of your home.
2. Either spend the time necessary to learn investing (researching online is free) or partner with one of the investors from #1 above and earn a little on each deal until you feel you no longer need a partner.
3. There is private money all around you...you just haven't approached them. Family, friends, co-workers, retiree's, etc. If your past flips were profitable and on budget, if you have a solid crew, and if you're buying homes at 65% (+/-) of ARV, you can put the details of your past flips ( on paper (pdf) or in a short, professional looking video and be prepared to send the pdf or video link to potential private money lenders who you are intentionally seeking out. You're not looking for retiree's that are living on social security, you're looking for retiree's with money that is not working for them in a way they need/want it to.
Paying someone $25K of "introduce" you to people is absurd. I've been flipping, buying/holding, creative financing, etc for 24 years and can tell you that most people who come to me after paying a guru $25K to $50K have been terribly disappointed once their money is gone and they have nothing to show for it. $25K will buy you a lot of marketing.