I thought the numbers could work, but the problem is selling a home with an indoor pool.  

Unless you are able to open up the closet space where the water heater currently is (assuming it is indoors) and use it for more living or storage space creating value of usable interior space, then I don't see why you would want to spend more money on tankless as opposed to the less expensive tank heater.

Example: hardcore indoor chainsmoker for about 35 years.

She would get drunk, makes a lot of noises, smokes indoor and claimed that she lives in the building.

Indoors, this can be deadly.You can always use round vent "pipe" to take the dryer vent from the dryer's location through the crawl space to the nearest outside wall.

The cool weather of fall will be here soon and many insects/rodents try to find their way indoors when the weather changes.

Growing pot indoors isn’t exactly easy and most people would rather go buy it than wait 4 months to get some half assed pot.

For many technical reason, these digital sensors all work better at capturing light at daylight temperatures than at the more common warmer indoor lighting temperatures.

We ripped off the "indoor jacuzzi room" and breakfast nook because they were horribly done additions that were already falling off the house.

As others have said, you can have one outdoor unit to 2 or 3 indoor units.