Now the wholesalers are desperate to make their (way too high) margin selling a house with no D.D. period at all. 

I have had issues with every single property I've owned, from fires to floods to squatters but I've always come out on top because I gave myself such a big margin. 

I took marginal deals years and years ago back in the past to learn experience.

Not saying they will lie to you, but everyone does their calculations slightly differently and may not be using the safety margins that you are comfortable with.

If these are $700+ units that is a fairly tight margin. 

If my house is only marginally cash flow negative, say $200-300 per month, does it ever make sense to try to build up a little more equity before I sell / try to ride the market higher?

I won the court battle and became a full time father (which in and of itself is a major undertaking) I then started a consultation business and helped over 2 dozen businesses flip their margins.

The capital gains tax rate on the sale of personal property you held less than one year is the same as your marginal income tax bracket rate.

I am in PA.Deals with substantial margins may be rare the auction route.

Once the process starts to take up all of my time and the profit margin proves to be large enough to support me, I plan to leave my day job and put all of my time and focus on growing this small side business into something much larger and more profitable.