Need to haul away couple of run-down park owned mobile homes if i buy this property.

I don't know your volume, but you seem to be in for the long haul and could certainly pick up business.

I have no time to use them and like @Aaron Mazzrillo said it's better to let your assets pay for your toys. 

We also had to get a special haul route permit because of the amount of dirt we were excavating. 

What do you think it will cost to haul it say, 70 miles away?

No matter how you want to factor things, including opportunity costs etc, you're going to come out ahead buying over the long haul.

I think when we get past the build up phase of our rental company in the next year or two, we'll get a new car in order to try and make the good old mini-van last longer for hauling.

This might be a better use of the money at this moment in time.12) Start looking for a w2 job that can pay more.13) do some side work on fiverr or upwork.14) Sell the toys (dirt bike, jetski, ATV, quads, etc)

After tow truck fees and a hiring a flatbed semi to haul the trailer home, I wrote a check to my friend a new trailer so he could replace the old one. 

The only thing is to keep in mind that the market will shift over time so if you're in it for the long haul, you should be fine.