The 1/4" foot for your Viking is an attachment foot to the walking foot. Yes the $$'s add up but you can get both from your Viking/Husqvarna dealer. I have both. I ordered both when my husband bought me my new machine. I had had my old one for over 30 years and it does still work. But now have one with all the bells and whistle ( which I don't know how to use all but I have them for whenever.
Hope this helps.