Building an RV Park from scratch under 50k?

I was going to build one a couple times, had the land, plans, engineeing, cost of permitts ect. I seamed to me to put in a manager to run it and come out you need 200 units.
Now Im looking to build a park model one 22 acres water,ele,sewer on site. trying to see if I want to put the plug and build it.
Would sell the unit out right with the lot, I would have to carry the paper on them also.
I don't have that good of fealing about the up coming years for business.