The more I have paid for any of my machines is $70 (60€)
Not two days ago, at my local thrift charity store, I found a Bernina Record 730 complete with all the accessories. it was priced 25€ ($28) but since the cord had been repaired in an odd way (yet not dangerous) the salesperson knocked 5€ off the price and told me he'll look for another cord for me...
Yet, this being said, in my online travels, I have found that vintage sewing machines don't really have a market in France, even Featherweights tend to sell for a fraction of what they would in the USA