Allen, this is how I would look at it. How much does it cost to build out each pad in total? A lot of times for these types of construction projects a lot of your cost is borne the day you start to dig. Which is to say, you will spend less money in the long run building more/all of the possible sites at one time than you will building them slowly.
Once you have that number. How long will it take to lease the sites up? You will incur costs from the start of construction through this period ie; time (time value of money, opportunity cost of oyur time), interest (if you are financing it, either from a bank or third party), marketing (to lease up the sites), and possibly others
Finally what will the lots rent for? What will you make on them?
Once you have all of that information you can calculate your return on investment. Take your NOI generated from the new sites divided by the total cost
Is that return higher than what you are getting elsewhere? Then go for it!
