My response from your other thread about this subject...
Hi @Dianne Pettitt , do you have any more information? Are you asking if the company is legitimate or if it's possible to double your money in 3-4 years in this area via multi-use? Either way I don't think anyone would be able to give you much help unless there were more info to be had.
I would be extremely skeptical of someone that would say you can double your money in such a short time. It will take at least this long to develop the land and then you would have to obtain leases or sell whatever it is you're developing. What is their strategy? Develop and operate? Develop and sell to an operator? These exit strategy would be essential to know how you would "double" your money.
How did you get in touch with these people and what is their track record? do they have any referrals or a book of past projects that have similar performance? These would be just basic starting points for me if I was going to invest with anyone, much less anyone I didn't already know something about, and possibly thought could be illegitimate.