I know I likely wont see a whole lot of appreciation (if any) on properties in these areas but part of me feels like there is some real potential to make some money over a 10-15 year holding period, especially if I can knock $10-15k off the asking price.

I like to step out of my comfort zone and explore new areas and analyze for potential then stick first.  

Do you actually pay every time a seller just expresses potential interest in doing a deal with you, or have you found a feasible way around this?

I suggest checking the area in person and meeting potential future team members like property managers , contractors, lender, and etc is a good way to get into the right neighborhoods.

Try to get as much info as you can and find out what other parks are charging for lot rent to see what the true potential might be.Good luck!

Keep analyzing, love the house hack idea but definitely include that in your potential rent in case you decide to move out, have both scenarios and see what works for both now and in the future.

What’s the benefits for the homeowner and potential buyer?

And the latter is where you can potentially meet a mentor or find partners. 

Meeting PRO's and networking will help you with finding the right properties and potentially partnering up with other investors. 

I have found a lot of potential properties around a new casino in my area.