I've got a chance to pick up one in Flint in 48504.Rehab started with new subflooring and drywall hung.Would sell it for $4k.My question, is Flint worth taking this risk?

You can do this using a kind of recession proofing 1031 exchange - Sell properties that have profit and depreciation worth protecting. 

We have plenty of comps that show that the house could sell for over 500k for a quick sale.  

agree with the other comment, different markets are doing different things. also, "be greedy when others are fearful." what people might be afraid of is, lots of commercial ARMs coming up on their rate adjustments, & the new rates (compared to 5y ago when they first purchased) will kill their cashflow, so they'll sell, and if everyone is doing this at once, supply might outweigh demand, everyone has to sell for less than they planned, and everyone who hangs on to their similar properties gets to recalculate their estimated mkt value with the new going cap rates. i don't personally think this is going to cause as insane of a shift as some people do, but it's all speculative, we won't know til it happens. if you can find a deal that pencils with 30y fixed debt, do it. 

If you feel you can do better, then it may be time to sell or 1031.It depends on what you plan to do with the money.

We were selling new construction for $140k just 4-5 years ago but now in that same area, duplexes are reaching over $500k.

I am a broker here that will sell about 150 properties totaling 35 million this year with 70% of them being for our investors. 

The other thing to consider is the original owner has died, leaving the estate to his sister and nephew to sell.

Personally,  I hate selling unless I am 1031ing beacause who likes paying taxes?

Is there any way around the tax lien being paid upfront when selling a property?