As a wholesaler, a seller approached me with a 48 unit apartment complex, 7 duplexes and a 2500 sqft Single family that he wants to sell (all of which occupy the same block.) 

Yes - you should budget all the associated "costs" with the rehab including renovation costs, holding costs, selling costs, etc. 

It seem like a great long term hold with the appreciation BUT I think selling would be ideal.

Aha it seems like every time I sell one of mine its the time.

It's typical to sell 40k programs to people after the free or low money get together.

The larger ones are selling for 300 to 350 per square foot new construction depending on the lot.

The idea was to upgrade the units significantly and raise the rents, then possibly sell once stable.

Like in our area, most of what I see hit the MLS there goes under contract quickly, so would be nice if you can find someone selling off market. 

It was written before the days of YouTube, so it's not full of the common nonsense where authors sell a course, send you to their website for downloads, or write a follow-up with additional "secrets" they forgot to put in the first book.Long-Distance Real Estate Investing by David Greene was another good one.

I had a client that had an illegal garage rented out for $1k per month and when he attempted to sell the property, the tenant went to the city and the owner had to pay the tenant back 2 years worth of rent.