It has been my experience that the value of mirrors is limited to 3 categories.
1. It is someone’s memory, …. aka family heirloom.
2. The mirror frame is needed for replacement, ….. aka an antique dresser.
3. Reconditioned and in perfect shape, it is pleasing to someone’s eyes who wants to hang it on a wall.
In other words, …… the mirror frame determines the value, …… not the mirror itself.
Thus, my opinion only: replace the mirror with clear glass and it is worth more as a beautiful “picture frame”.