I want to buy about 20 acres of raw land to build on one day.

@Ike Ekeh @Justin R. has pointed out one of the major points that will determine your price points and targeted markets for solicitations.Another thing to consider is the portfolio mix, Are all the parcels 100% raw land or do some parcels already have Sewer, and Utilities already in place?

Raw land not actively developed is always considered an investment.  

I currently own my home with about $50k in equity, plus 8 acres of raw farmland with $30k in equity.

I find many of my clients like that I also invest in all market segments, SFR(mostly), raw land, airbnb, small MF. 

That said people are raw after an incident like a fire, set expectations on repair timelines being long.

Raw Land!

I'm a newbie but planning on avoiding raw land only because I don't see it selling.

I would steer clear of hard and fast rules like the 70% rule in general, they are too broad and don't work in a lot of markets in Southern California for example there is no way you are getting a house at 70% ARV -expenses unless it is off market and you are comfortable taking advantage of someone, or maybe raw land. 

So just bought a nice 2 acre piece of raw land to flip and not sure what to do with the storage shed (image attached) that's on it.