A house in (random B class neighborhood) the midwest/south costs 100k and rents for 1200.00 a monthA house in (random B class neighborhood) NYC  costs 800k and rents for 2500-4000 a month.Why on earth would anyone wanna buy in NY???

Don't buy in the roughest neighborhood in the urban core.

NYC uses a magic formula (statistical analysis) to figure out how much your property is worth based on comparing size, style, and age of your unit with your neighborhood. 

Zillow, Redfin, Trulia, local county website, Google Maps/Earth, etc....you can get a pretty good idea of the condition and neighborhood most properties are in just using available technology.   

Reading a lot of books, driving around my city (I actually found a bunch of really cool neighborhoods), meeting up with agents/lenders and letting them know of my plan, and going to local RE events.

She gives a pretty decent breakdown over the different neighborhoods of Milwaukee.

@Jeff Engstrom Hi Jeff, I have a deal under contract in a neighborhood adjacent to Uptown.

I know that Poland is a more expensive and nicer neighborhood.  

Many people in my neighborhood have illegally converted their basements into second units and rent them out by the month at $900-1500/month, but my husband would lose his play space, so we even don’t do that. 

When looking at Cleveland with those out of state eyes many have found The Ultimate Guide to Grading Cleveland Neighborhoods to be a great resource.