Do toy story plushies increase in value?

The verified evidence does not contain any information about the market value or appreciation of Toy Story plushies. The only confirmed entity is "Toy Story" itself, and the second source is unrelated to plushies. Therefore, based on the available data, we cannot affirm that Toy Story plushies increase in value or provide any reasons for such a trend. Any claims about value changes would require additional evidence not present in the provided sources.