Sadly, I really think you got ripped off. I have three Janomes and the one I use all the time (Janome 6260) I've been taking in every year for about 6 years. The cost has always been $70.00, occasionally a small part is replaced - no additional charge. The other two I take in every couple of years - always same price.
Missouri Sewing Machine Company, been in business here since the late 1930s. Always very helpful, whether I buy from them or not.