Here's another one that also includes the bobbin, but the Buy It Now price is too high, IMO - as many of these machines as there are around, parts are as common as toast.
I might email the seller and offer him $25 for it - if he accepts, you'll have a complete set at a fair price. If he doesn't, then there'll be another set along momentarily.
http://www.ebay.com/itm/SINGER-SEWIN...item53ee402f6b