How do I know if I am doing well in real estate investing?

[Douglas Gratz]

Hello friends, Hope everyone has a good thanksgiving! So, I started in real estate investing about 3 years ago. I currently have 4 units , two singles and a duplex. All properties are in Norristown PA 1) My duplex cash flows approx $600/month and cost me all in $87k 2) Singles about $300/month. and each cost me all in a total of $90k each That being said, I am having difficulty measuring if I am on the right track to doing well. I look at properties in somewhat below decent neighborhoods in Philadelphia that cost above $150k . Rent is lower there because taxes are lower significantly and after some analysis cash flow on these 150k-250k duplex’s and triplexes are between 400-700. So in Norristown I am paying significantly less for about the same cash flow . What I do not understand is how people make money on these houses I speak about above. I wonder because I would like to buy in these Philadelphia neighborhoods because they have a better chance of appreciation and resale down the line. But if I finance a 200k house my monthly payment would be around $1000/month, about $1300 after taxes and insurance. So if I have a duplex in Philly and get on the higher end of rents $900 per unit I could cash flow 300-500 depending on expenses. So I guess my question are: 1) Am I making the right move when investing in Norristown where can buy two duplex’s for the price of one in Philadelphia? 2) I know this is hard to answer, but how would I begin figuring out if I am making good investments in my market? Any advice would be greatly appreciated, thank you for your time !