We have 3 bed /2 bath condo that is modern with nice appliances.Besides putting it on Airbnb and letting bookings roll in, how can I reach out to promote this property? 

@James Hamlingdefinitely agree with some of what you wrote, although I think China is going to struggle... seems like they are going to have a demographic crisis soon, although maybe it plays out differently than it would elsewhere since, you know, they're not a free society

Before taking this on I’d verify with the historical society and building department what process you need to go through to renovate and if there are any requirements on what you’re allowed to do or not do. 

There are some solid advantages here: new construction typically means lower maintenance costs upfront, modern amenities that attract quality tenants, and potentially higher rental income.

The quality of modern lumber is simply far inferior to the quality of lumber they were using to build homes in the early and mid-20th century.

But to your point, there is a pressure within society, as a whole, the be positive.  

Complicated rooflines, modern details that require a bunch of steel framing, excessively large great rooms, spa-like bathrooms, etc would push you into the $1,000-2,000 range.  

If you can get a property with a more modern floorplan at a similar price I would go for that.

Quote from @Ron BradyYou are probably right because modern society has a penchant for redefining words.

An existing kitchen layout might work well for adding a dishwsher or microwave hood for example allowing it to be made functionally modern without a major rehab.