As your deals get larger, especially when they are bigger than the equity in your home, a fix-and-flip loan may be worth considering.I'm happy to share my experience as an investor and as a lender.

A house that's similar, but 10% larger than another usually isn't worth 10% more.

This is where I would focus, as these are the same attributes that attracted those responsible for the larger projects like the Bellweather District you mentioned in your initial post.With your budget I would recommend NW Philadelphia (Germantown and Mount Airy in particular).

I am a little weary since I haven't done that before- not sure it would be enough to get me into buying portfolios or larger complexes though.. 

I'm still in the process of growing my portfolio, but have heard others 1031 all their smaller properties into a larger building and have a property management company manage, OR, set up a seller financing deal with another buyer that gives you the cash flow you desire. 

Higher Credit Scores allow you to get larger loan sizes or higher LTV options.

We are considering building a small multifamily a couple duplexs, a tri or quad in a small suburb of a larger city (ie Nashville, Knoxville, Atlanta, Ashville). 

However, after dealing with the constant headaches of repairs, complaints, and other issues, I made the decision to shift my focus to larger commercial deals in partnership with others.I have co-founded a coinvesting club, allowing me to diversify my investments across multiple deals.

It's a great path, but it takes time and energy.

is that a combination of larger down payments + paydown over the past few years?