I'd trust the listing for that, although that's certainly a wide range of lathe sizes for one item.? If you can share the link we can take a look.? You can probably get it cheaper if you find the model and have a service like shapeways print it and mail it to you, but it may not be a big difference in price.
You can also buy a perfectly nice 3d printer for around $150-200 these days, so consider that the part might be a significant fraction of the cost of a plug-and-play printer (e.g. a Bambu a1 mini)
I use a 3d printed threading dial on my 10k and it works great! I had a friend print the body and gear at 100% infill, then I turned a brass dial and press-fit that on a shaft.? I sanded the plastic parts, primed, and painted so it matches my lathe.? You can see the finished version here:
Hello all.? Have been following for some time.? This is my first post.? There is a 3-D printed thread dial indicator on Ebay.? I have a SB-13.? Will this fit my lathe?? The add says it fits a 13, 14 1/2, 16 and 24". It looks like it is plastic.? What do you experts think?? Thank you.