Quilt Mom is right. However, the 222 can be VERY expensive!
You'll love the Featherweight you end up with for portability, and you may find that you stop using your D1 !
As for what to look for on ebay... check the photos carefully. If they don't show the bobbin area, ask if the bobbin and bobbin case are there. Look for bad wiring, etc.
This one on ebay is one I'd consider:
http://www.ebay.com/itm/VINTAGE-221-...#ht_500wt_1413
Or this one:
http://www.ebay.com/itm/SINGER-FEATH...ht_6680wt_1392
And this:
http://www.ebay.com/itm/Singer-Feath...#ht_500wt_1413
I have no affiliation with any of these sellers, just went looking to see if I could find examples of what I'd look for.
Happy hunting! Let us know when you find her!