I paid $75 for my 1902 Singer 27 treadle with less-than-perfect sphinx decals at an estate sale not too long ago. All it needed to get it working was a little cleaning, oil, and a leather belt. I even tried a Singer button hole attachment on this machine and it worked beautifully. $350 for a treadle seems a bit steep, unless it is a rare model in very good condition. 66s are not rare, and with worn decals, definitely not worth what she's asking.