Because Detroit is the last major city in process of recovering from crash in 2007/2008.

So my question is -- what's the typical approach for arriving at a possible purchase value -- as it relates specifically to capturing the NOI in time, especially if it seems to be changing somewhat rapidly?

When the next recession comes (they historically happen every 5-10 years and the last one was '08),  I'm not confident that the population growth will outweigh other negative macroeconomic factors...I strongly doubt we will see anything like the '07 crash, particularly because of the affordable housing shortage, labor shortage, lending reforms, and all the positive migration, but that doesn't mean we won't see a pullback. 

How much value you do you place in old rent historical given that there is obviously inflation etc.Of course none of us has a crystal ball and rent can always come crashing back down with the change of tides... but I figured i'd start up a discussion.

I think it is almost always better to buy in an up and coming neighborhood than one that has arrived already.

How much value you do you place in old rent historical given that there is obviously inflation etc.Of course none of us has a crystal ball and rent can always come crashing back down with the change of tides... but I figured i'd start up a discussion.

Show your seller how you arrived at your valuation.

This kind of thing can only go on so long before his deck of cards comes crashing down .sadly it seems a lot of people have got screwed

Although I am not fully ready to purchase a property (still trying to up my savings), I believe that the time to do so may soon arrive.

Even with grotesque timing prior to the big crash in 2007-08, your S&P investment (had you held on through the turmoil) would be a valuable investment today (chart below).