Purchase price: $629,000 Cash invested: $415,000 Sale price: $1,350,000 Bought a 2 family home and gut renovated it into two condos.

On Craigslist I saw lots of "Fash Cash", "Quick Sale for cash", "We bug houses" type of ads, has anyone done such a transaction?

Purchase price: $85,000 Cash invested: $13,000 Sale price: $110,000 This was my first property.

In brief discussion with friend he mentioned the tenants offering a $300K down payment, he did not mention if they talked sale price.  

This will make the future sale and all income easier to track and also reduce my liability exposure.

Short-sale, on the MLS, let the agent double-end the deal.

Purchase price: $160,000 Cash invested: $21,400 Sale price: $253,000

Although I have some income from direct marketing and book sales, for many years 95% or more has come from real estate but different aspects of it like rentals, flips, holding paper and managing/contracting.

If they are for sale, your agent submits an offer like any other. 

This is simply a standard sale on a time crunch depending on teh foreclosure status.