That is a SUPER find !! Have fun !!
I check our Goodwill every few weeks but NEVER find anything like that ! They rarely ever have any fabrics or sewing items. Keep hoping I'll find a good old Singer or Featherweight machine but so far, nothing ...
Our Goodwill stores here also charge too much $$ for stuff, I often see a lot I could buy NEW at Target or WM for less ... makes me wonder why people shop there ??