Here is a list of highlight that you may take with a grain of salt, because they are from a high priced market like SF Bay Area:
1. The types of home that keeps the value is the ones in good school district, because people are always trying to put their kids in good school and it is not always about ROI financially. Those are the high price districts that rarely drop, and people don't sell unless they retire and move out of the area. (i.e. Cupertino, Evergreen, Fremont, Black Hawk, etc).
2. Make sure your mortgage has no points or fee, even if the rate is higher, because you most likely will have to move when your need changes later (i.e. more income and move to a better house/school district, find a better job in another state, the price rise so much it is worth selling and move somewhere, the neighborhood go downhill and becomes a ghetto, etc). Keep yourself flexible so you have less to lose. Make sure if you pay off the mortgage early there is no penalty.
3. Get a fixed rate, as a defensive move and you will not need to worry about rate reset.
4. Check for things like HOA or property tax rate, those affect the long term value compare to the nearby area with differences in HOA and tax rate. $300/mo in HOA turns into $100k in 30 years.
5. Not sure about in Nashville, but in the bay area it is always the location that worth the price. A new house in Stockton could be only $250k but a run down, needs to be tear down house in San Francisco could be $700k. It is the commute time and distance that makes the differences.
6. Renting could be cheaper by a lot, because the rent you pay may be much lower than a mortgage interest even after tax deduction, that it makes sense to rent and save the money in CD, especially when the price is dropping. Don't wait too long if you think the price is bottomed out and the next boom starts, and you miss the boat and have to pay more.
7. I think paying off a mortgage first if you have extra income is a wise choice, because it has no risk and fixed return. Now if you are a stock wiz is always generating way higher return in your investment (unlikely) then you may be not want to do that. For most people, there is no better investment with such a low risk. Some people keep buying bigger and bigger houses because their income tax is getting too high, and need a big mortgage to reduce taxes. In those cases this is also not a good idea, if you can find a better way to use your money.