All the previous listed ways to market will work if you are dedicated to the practice of sending letters and following up. 

I am looking to make my money work for me on the side but don’t have too much extra time to dedicate .

There are several books including mine that have a chapter or so on the subject but as for one dedicated to it you might reach out to @Jessemccue on BP  and see what he recommends.  

Can be a portion of a room that is dedicated exclusively to business if the division is clear

If you could offer some fixed rate Pricing that might help at least to get started so the investors know exactly what they are payingAs far as more specifics on price, dissect the current deal that you are doing and try to lay out how many hours you are dedicating to these tasks, multiply it times some rates estimates and subtract it from your final margin you will quickly see the impact on the margins and why I say it will cost sensitive.  

I like making my tenants happy, doing extensive vetting of tenants, the challenge of filling a vacancy as quickly as possible by being selling my property to prospective tenants, creating a great team of contractors around me (no, I dont do any work myself), and being part of a family of owner-mangers who know what it feels like to watch that ROI increase with diligent and dedicated work. 

sorry you got taken.. do watch the American greed episode on Remington financial or google Ingrid Robinson American greed she has a website dedicated to your exact scenario.. she too had a dream to build a retreat and was also taken.Bottom line these folks prey on those that are dreaming.. 

  Getting to 50 units can be a lot of work however I can agree with you in saying that some people will not get there only because they will not dedicate themselves to focusing on making it happen.

I am very dedicated to learning and willing to exchange my time, effort, and full attention to learning this field of investments.

Word is soon no more ring clamp meters, instead will be CT (just like 3 phase) Many panels I do now are dual meter, 2nd meter is billed at lowe rate dedicated to EV charger.