Hello, I haven't lost my stylus yet, but I find this one:
https://goodereader.com/blog/product...acement-stylus
Any stylus for WACOM will work to write anyway, however the erase function (the main important feature) won't.
So I recommend go for the link or try something in china where they sell more Boyue e-books.
I find US$35 a big amount :-/. Hope it helps