Looks nice to me, and seems worth $15 based on that alone. Why not get it? If the mug does not clean up, then you can always have the metal silver plated and be really fancy.
The boar knot looks in good enough condition to clean and use. If it compares to an Omega or Semogue it's worth the cost all by itself. The handle is vintage so if the knot falls apart it can be replaced for a great barber style brush that'll give years more service. Can't quite read the logo on the mug bottom. Doesn't look damaged. Is the glass or ceramic liner separate from the silver metallic holder? Could do a scuttle like heating of the inner to keep lather warm while shaving. That type works well for dropping a puck of soap in, loading, & face lathering.
The brush alone (cleaned and re-lettered) would be worth twice that price. I'd re-letter it in yellow ..... it really pops.
cool nice find sir you never know what kind of good stuff you'll find in a antique store that's how I found my gem and straight razors
