For me, “collecting” is a personal thing where I want to feel there is value in the things I have (or am lusting after), and not always is that about monetary value - that being said, I wouldn’t like the thought of losing my proverbials by buying something that will go to zero value once I walk out of the store.
There are pieces I have that make me happy I have them - because I like them, possibly partly due to the hype around them, but also because I feel the value will hold and it will be one less reason for my wife to want to kill me

Other pieces I have simply because I find them interesting, and likely someone else will also find them interesting (though perhaps not as many as with the old reliables of PP or Rolex). This they could be considered “collectible” for various reasons in my opinion.
I think building a collection is about having a mix of things that you like, with some as general foundation pieces in terms of design, movements and of course values, but others that are more indulgent in a just-because-I-like-it and to hell with the value down the line (of course depending on the purchase price too!).
I would hazard a guess that with the popularity of the Singer brand, there will likely always be some sort of market for these limited prices. And either way, if you decide to pick it up (I don’t know if it’s either/or with the Moser) you’ll know that you have something quite rare on your wrist, and won’t bump into anyone else with one (probably) which in itself is a nice “value” to have

All the very best in your decision Jim.
Niall