If you own both the real estate and the note/mortgage that gave rise to the foreclosure, then the redeeming party must pay the full payoff of the note with all accrued interest, not just the courthouse steps bid price. 

@Kevin L. buy a home that you can improve and add value, including turning the garage into an ADU.Also, take the ugliest room and rent out the rest to generate income to offset the mortgage payment or to accrue cash for improvements or additional investments.

If you ultimately take the property the extra years of taxes that accrue can eat into your profits or even cause you to have a loss. 

You're not actually accruing any more debt you're just paying a fee at a later date for the right to take out equity directly without any monthly payment.  

@Holly PetersonWe see many lending in a junior position and not checking on status of the first and then the first goes into default and accrues very high interest that eventually wipes them out.Always make sure you understand full picture

If a buyer has the financial capability to handle possible temporary negative cash flow and ability to refinance in the unlikely event the note is accelerated, and the seller has the ability to do a background check on the buyer and reach an intelligent decision, then the benefits of a real property transaction without the expense, time and qualifying necessary to obtain new financing and perhaps the benefits of a lower interest rate can successfully accrue to the benefit of both parties to the transaction.If the buyer is an undercapitalized inexperienced recent “graduate” of a guru program and the seller is willing to sell to anyone, whether breathing or not, then the transaction has a high likely hood of ending in disaster.When both parties are knowledgeable and understand the risks of the transaction, nobody is “taking advantage” of anyone else.  

The key features that make it more efficient that are hard to replicate else where is that the interest is simple interest similar to commercial loans (rate/365Xbalance daily), there’s a 20 day grace period before the prior period’s accrued interest is billed/added to your balance outstanding so you can keep chipping away at your daily principal balance with your deposits from days 1-19th each month before prior month’s interest is even billed (on the 20th/21st usually).The current CMT or constant maturity treasury index is less volatile than prime index that most heloc’s are based on (most bank commercial lines are based on 3-5 year FHLB + 225-275 BPS or 2.25-2.75% margin).

The loan is interest only and it accrues and is paid when the loan is paid off - there are no monthly interest or principle payments during the life of the loan.

Plus with each sale they get principal returned.. so its not like all accrued and then you get it at once. 

Wait patiently for the tenant to buy real estate, then record the judgment in the county where the property is located in order to obtain your lien -- the balance of which has been accruing interest nicely in the interim.Anything else is a waste of resources.