That really depends on how badly you want one and how lucky you are. Are you talking about the card table? I have heard of people finding them for $25. However, I have a card table for my Singer 301 for which I paid $80. Then I have a card table for my Featherweight for which I paid $150. that is a lot but it was important to me to have the table so that I could have the machine flush with the table.
You can purchase a reproduction one from here
http://www.jslyle.com/model221.htm for 177.50 plus 41.50 for shipping. I had considered this before I found my table on craigslist.