Just last week an alumni stopped by who is working on a 80 million dollar international real estate development project of his own where he got funding through investment firms.

@Waylon GatesFollowing are the similarities and differences between the solo 401k and the self-directed IRA.The Self-Directed IRA and Solo 401k Similarities Both were created by congress for individuals to save for retirement;Both may be invested in alternative investments such as real estate, precious metals tax liens, promissory notes, private company shares, and stocks and mutual funds, to name a few;Both allow for Roth contributions;Both are subject to prohibited transaction rules;Both are subject to federal taxes at time of distribution;Both allow for checkbook control for placing alternative investments;Both may be invested in annuities;Both are protected from creditors;Both allow for nondeductible contributions; andBoth are prohibited from investing in assets listed under I.R.C. 408(m) .The Self-Directed IRA and Solo 401k DifferencesIn order to open a solo 401k, self-employment, whether on a part-time or full-time basis, is required;To open a self-directed IRA, self-employment income is not required;In order to gain IRA checkbook control over the self-directed IRA funds, a limited liability company (IRA LLC) must be utilized;The solo 401k allows for checkbook control from the onset;The solo 401k allows for personal loan known as a solo 401k loan;It is prohibited to borrow from your IRA;The Solo 401k may be invested in life insurance;The self-directed IRA may not be invested in life insurance;The solo 401k allow for high contribution amounts (for 2016; the solo 401k contribution limit is $53,000, whereas the self-directed IRA contribution limit is $5,500);The solo 401k business owner can serve as trustee of the solo 401k;The self-directed IRA participant/owner may not serve as trustee or custodian of her IRA; instead, a trust company or bank institution is required;When distributions commence from the solo 401k a mandatory 20% of federal taxes must be withheld from each distribution and submitted electronically to the IRS by the 15th of the month following the date of each distribution;Rollovers and/or transfers from IRAs or qualified plans (e.g., former employer 401k) to a solo 401k are not reported on Form 5498, but rather on Form 5500-EZ, but only if the air market value of the solo 401k exceeds $250K as of the end of the plan year (generally 12/31);When funds are rolled over or transferred from an IRA or 401k to a self-directed IRA, the amount deposited into the self-directed IRA is reported on Form 5498 by the receiving self-directed IRA custodian by May of the year following the rollover/transfer.Rollovers (provided the 60 day rollover window is satisfied) from an IRA to a Solo 401k or self-directed IRA are reported on lines 15a and 15b of Form 1040;Pre-tax IRA contributions on reported on line 32 of Form 1040;Pre-tax solo 401k contributions are reported on line 28 of Form 1040;Roth solo 401k funds are subject to RMDs;A Roth 401k may be transferred to a Roth IRA (Note that from a planning perspective, it may be advantageous to transfer Roth Solo 401k funds to a Roth IRA before turning age 70 ½ in order to escape the Roth RMD requirement applicable to Roth 401k contributions including Roth Solo 401k contributions and earnings.)

Cash on cash, internal rate of return etc?

Joe's brother-in-law buying Joe's house at a short sale would be a huge red flag for fraud.I think the biggest arrow in your quiver is #1, and your most probable path to success is to order a fresh appraisal with a fresh opinion of value, and once it comes back go to your (or the end-lender's) appraisal department (not the AMC, the lender's internal folks) and argue that the new appraisal is more credible than the previous one because of #1 ("if the appraiser didn't even go to the comps for a quick drive-by photo, who knows what else he didn't even actually do?")

You can transfer it back to the llc and hopefully it won't trigger the due on sale clause.

It appears to be on a reservation because the Bureau of Indian Affairs is involved, @John D. and it also appears that that it may be a contract for deed (land contract, installment sale contract) where the seller received full payment over time, but never transferred the ownership to the buyer even though it was fully paid by the end of the contract. 

If you purchase a property and inherit the tenants, tenants who most likely paid security deposits at one point, how is the legal transfer of the security deposit money handled?

Optional - Get a college degree in real estate ( Florida International University and University of Florida offer fully online degrees in International Real Estate and Real Estate Finance).  

The seller tells me that the county will require an amount equal to 1.5 times the amount of a septic system replacement to be put into escrow in order to transfer title.  

In the past, I've accepted checks with no problems and online transfers with no problems.