Developing out a new mobile home park

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I am heavily considering building a mobile home park from the ground up and installing new single wide units that will be park owned. Has anyone here developed a park from raw land? What pitfalls should I look for? I know that park owned homes are not the preference, but my roi would be much bigger and the homes (even brand new ones) will pay off fairly quickly. My numbers are looking like about 750k to purchase and develop a 35 unit park that will be rented for $450/mo space rent, or $850-900/mo single wide. Acquisition of brand new single wides would pay themselves off in 3 years and development would be paid for in cash......So while I would be floating a ridiculous amount of money for three years, the annual return of 350k after that is amazing. 

Is there something I'm just not seeing?