In a standard scenerio, I would suggest calling a few more times, text and email, but also start looking for alternative solutions so you dont lose the deal. 

BAnks have them.. as well as others.then there are registered investment advisors that can sell away IE they search out alternative ( usually real estate of some kind) and they get paid by whoever is selling the deal.. and sometimes the fee's to them are quite large.

What is fueling the market and who is buying houses there? 

Alternative, raise the house on stilts like they do in flood zones.Either way, not worth it!

There are alternatives and you can message me for some additional information. 

Yes, we’ve been contemplating the pure sell option.The alternative we’ve been discussions is to rent this out short term (1-2 years) while we purchase another 1-2 properties in the area as we potentially move into the original propertyYou’re absolutely right that we should leave emotions out of it, I just fear the future cost of acquisition will go up as neither my wife nor I are big into flipping

However, they did eventually catch up as people were priced out of SFR and started looking for lifestyle alternatives. 

I would trade them in and get two reliable, fuel-efficient cars like a Honda Civic.2.

Alternatively look for ways to passively invest.

I understand they may want to limit viewings to serious buyers.The alternative is to write the viewing in as part of your offer along with the usual financing and inspection.