If the tenant leaves, it could be challenging and costly to modify the property for a new tenant.Market Risks: Like all real estate investments, NNN leases are subject to market risks and economic downturns.

Excellent tools covering market research, financial planning, and a variety of investing methods are accessible.Examine several real estate investing categories, including multifamily, commercial, and residential properties.

Is the risk/headache/costs worth the excess return?

And, as you and others have said, you're now at big risk of holding open a place with no leverage whatsoever and if they pull out, you have no practical recourse and are likely out a month or more of that $3,000 monthly rent while you try to get someone else in.

Please be very careful if you are risking your dad’s home on flips. 

If I've learned anything from other real estate investors, you may cycle through several contractors/handymen.You got this! 

High enough to justify the risk.

While I haven't found my Dad's next house yet, I have watched several new friends get theirs and also start investing the subto way.The community itself is incredibly active and engaging, with members eager to share their experiences and offer valuable advice.

It's a pretty good investment market, especially for those with any tolerance to risk.

Risk/Reward- you can add as needed.