A 50K duplex will most certainly be in a lower income area.  

What I've noticed is that in general, people are not really getting their money's worth out of major remodels in the lower end condo areas.

You don't have to go 80/20, you can go 60/40 for a lower payment and (sometimes) a slightly lower rate.

Some items were reduced to reasonable levels.

The neighbors get foreclosed on more than typical neighborhoods and that keeps values lower for longer.2) HOA association decides to levy a $20K assessment on all owners in the neighborhood in order to upgrade everyone's windows, decks, roofs, and siding.3) HOA increases monthly dues by $250 per month in lieu of a large special assessment. 

It sounds like the lower response rate of postcards vs the yellow letters is a good thing?  

It's higher in rougher areas and lower in nicer areas.

Our numbers dont work out until about $500K is it unheard of to go in at such a lower offer?

I use http://www.resimpli.com/They seem to be priced significantly lower and have great customer service.  

The above assumes you're having a good level of interest in the property.