I'm also in the group that believes that TH should appreciate well.
The absolute majority of buyers from resellers are people who didn't buy back when a set was commonly available. And the surprisingly small time frame means that comparably few people bought it from regular retailers, thus increasing the number of aforementioned potential buyers.
Historically, being a modular set alone has been reason enough to receive nice gains. The target audience is among those with the highest liquidity / willingness to spend, And this one has everything going, neat looks, attention to detail, biggest modular of the whole series, unique concept, low supply stocks.
Of course it's very hard to give reliable predictions for the value at a given future date. But unless there's some drastic unforseen event, I'd be very surprised if prices won't rise steeply.