Consumer products, especially electronics were generically dependent upon economy of scale i.e. with more people buying a product, the price tends to go low.
But with latest advancements in material science such as 3d printing, semiconductors there is no reason for accessibility products to cost so high; especially when niche/luxury products in this categories are priced lower.
As you rightly said, this seems to be a double whammy. Yet, I would like to point out few companies developing revolutionary products for accessibility and pricing them reasonably such as - Stabilizing handles for spoons and other attachments from https://www.liftware.com/, Game controllers from Microsoft (https://www.xbox.com/en-US/xbox-one/accessibility).
There is definitely need gap for high quality, reasonably priced, accessibility products.