@JD Martin "Clean and guaranteed title is the bedrock of real estate investing." = Interesting perspective. Profit is the bedrock upon which I seek to build a real estate investing business, -and a clean title is merely one of the important tools used to build profit. However, there are ways to work around any tool that is missing. Not faulting you or @Nick Brogren for walking away from any deal that doesn't suit you. Still, clouded title situations often make excellent cash flow opportunities as rentals that can be held for the number of years required to eventually obtain that clean and guaranteed title.
The profit in properties which lack clear title, need not be dependent upon a quick flip. If the acquisition cost is low, (past due taxes, and the cost of a quit claim deed), the rental income alone can provide an excellent ROI in the short term (1 to 4 years while waiting for clear title). Then in the longer term, an eventual sale after clear title is obtained offers even better profit potential.
Nick, before walking away from the property, why not negotiate the price of a quit claim deed from both the resident relative and the gentleman who wants to sell? Find out what it would take to acquire their interest. Be certain to explain to the resident that the county will be foreclosing and he/she will then be forced to move. Similarly, explain to the gentleman who wants to sell it, that without documentation regarding his claim on the property, his interest, if any, is not worth much.
Provided that you can negotiate an agreement from both relevant parties -to quit claim their interest in the property to you for a modest amount (a hundred to a thousand), then proceed with the title search to find out what liens there may be. Most liens, other than mortgages, will be beyond Minnesota's six year statute of limitations anyway. I doubt they will matter.
http://marsomichelson.com/statute-of-limitations-old-debt/
If you like the title report, then you can proceed to acquire the quit claim deeds. Once you have color of title from the quit claim deeds. I'd pay the past due taxes, or maybe just enough of the property taxes to keep the property out of tax foreclosure, and meanwhile lease/rent the property back to the relative who is in residence so he/she doesn't need to move. $500 a month in rent on the property would repay you for the cost of both quit claim deeds and the past due taxes in just about a year. The property could then provide you with a modest cash flow for how ever many years it takes you to build a marketable title. No need to put remodel $ into the property until your title issues are handled.
No need to hire a law firm to find out if anyone will fight you for the property either. You can file a "quiet title action" yourself and your title company will tell you who needs to be notified in order for them to insure the title. If no one responds, then your request to quiet the title in your name will be granted. If a relative does respond, then you can negotiate with whoever responds, withdraw your Quiet Title Action, ( http://www.wikihow.com/Withdraw-a-Lawsuit ) or hire an Attorney at that point.
The bottom line is that, provided you are patient and careful, clouded title properties can be turned into large profit. And you'd be learning to master a nitch that your competitors tend to avoid.