Donnajean, I hope that my much lowlier machine would not cost so much - I do not have any problems that need fixing at the moment, but I do want to keep it that way.
Tartan, they do not have loaner machines - and my machine is actually still running like a dream, I just worry about lint building up where I can't get at it, and the fact that it has never been oiled (my user manual only tells me to keep it regularly cleaned (and shows how to get into the bobbin area), 'no lubrication is needed'). When you say a drop of oil on the hook, would this run the risk of getting the thread oily?
Thank you for your replies!!