Hi Carol,
I have a couple of 401s. If I was having the problems that you mentioned, I would try to replace the hook myself instead of paying someone to do it. There are a few websites that have resources and replacement parts. You might also be able to find the part on ebay. I've never changed the hook but I do take the bobbin case out of my machines when I am cleaning my machines.
Send me a pm and I'll be glad to give you the links to where you can get your repair questions answered. I can't imagine that it would cost $150 to repair this item....but as I said, I've never worked on the hook before.