Here is a low cost option. Not sure how it performs and what the QC is like.
https://www.svbony.com/sv190-ultra-f...eyepiece-uf10/
It is available at Amazon Au for under $69 (Australian stock, free delivery) or $99 (free international delivery). Not sure why anyone would buy the more expensive option unless the local one sells out.
Perhaps someone has one and can comment on how it performs in a Newtonian with 1520mm focal length given the eyepiece has a flat field. I would think the field will remain flat in a flat field telescope such as a Tele Vue 101 but I would expect to see curvature in other telescopes. The eyepiece itself just won’t add or subtract any extra curvature.