well, you do NEED a walking foot! Even if you think you don't, you don't want to be knee deep into a project and realize, " I should have had"...trust me on that one!
I would say $180 is pretty steep, so shop around...and if you need to use a generic for a while, that is ok too! I have used them on several different machines...In fact I am using one from Kenmore on my Elna right now! Works great!
DO read about your machine though. You have to make sure that which ever generic you get, it is one that work on your machine as far as the feed dogs go! Some walking feet have teeth and some are smooth. A smooth bottomed one is generally for machines that the feed dogs go down, one with teeth is for the machines that just get the feed dogs covered. You need some traction! Happy quilting!