Until used houses get near the price of new houses they will keep going up.This is not because of banks lending to anyone and massive speculation. 

Definitely pick @Adam David Graning brain as he actually has a STR in Cape Coral vs. just speculating.

Many investors do not necessarily consider calculating appreciation given it is somewhat of a speculative measurement.

Of course this is all speculation as I mentioned. 

However, my income loss is also speculative which makes it hard to prove.

You haven't described the location or the condition of the home at any point during those last 10 years, so I'm left to speculate, but it is very possible that the sale for 69k could have been a very motivated seller.

It looks like you've been in contact with the seller and may have a gauge on their true desire to sell, which can help you determine whether the $600 for an appraisal is money wasted or a worthwhile risk.My supposition is the appraisal will come in higher than your offer, which will likely embolden the seller to stick to the appraised value or higher.

Further, the court rejected the servicer’s argument that the release of personal liability stated in the primary loan documents extended to the subordinate loan: it took issue with the fact that the primary loan documents did not reference the subordinate documents, and speculated that the servicer “could have easily included the language in the subordinate loan documents” in order to show that it was not attempting to reaffirm a discharged debt—especially after the debtor voiced “objections and concerns.”

This is all speculation at the end of the day as to which neighborhoods do better than other at the end of the day, but I have a great gut feeling on it.

If it cash flows, you can afford to keep it forever.The people that eventually get killed are those that speculate that appreciation will bail them out.