The concept of putting more cash in will pay off a property faster, but without using actual numbers, you can make any scenario look like it works.When you put your scenario into the real world, the timeline, the dollars in, isn't going to payoff a property in 6/7 years.Now, the most important part of the answer.You're missing the power of what leveraging can do with your cash.1 -  The object of REI, which is something you don't find in other investments, it NOT to own it...it's to CONTROL it. 

It is faster, I can get it done without trying to track down a contractor and of course it can save some money.

Trust me when I tell you that your $1 million can dry up faster than you think if you're not wise with how you use it. 

You are also allowed to negotiate a faster move-out which may result in less cost to you and less damage to your unit.

Property A will build up equity faster and you'll be able to use that equity to fund future purchases in the portfolio.

Additionally turn around time in days and if drive by exterior pictures only or interior as well adds to costs.They can run sometimes from 50 to 150 or more but generally cheaper than a full appraisal and a faster turn around in most cases.If you are looking for people to do free reports for you and get nothing in return that sounds like a flawed business model that might need to be revisited.

Far as driving for dollars thats the best way for a faster result to finding a motivated seller but not the only way. 

I could spend a lot of time and money there and end up effectively making 20-50hr on that task. or find a great wholesaler or 3 who are already better, faster, and connected, and pay the $5k on the deal.it's a wash in terms of dollars but now my time is free to focus on higher income producing activity. if I spend 10 hours all in on a deal by outsourcing the marketing and sales calls and make 20k in profit or equity that's 2 grand an hour. where would you rather focus your time?

With that in mind, if you could negotiate a smaller price and sell/give the homes to people to live in that will pay you rent could be a faster and less capital intensive way to get the park up and going. 

Modular projects will typically be built much faster than a site-built project.