What someone has paid at a garage sale etc..is it reality or luck? Asking what "you've paid" is kind of mute if you can look on ebay and see what closed auctions for 301's are. Then you have to decide to pay the asking price or not. I have 5 of them and I've paid all different amounts. Look on ebay.
Personally, I'd like a better look at that bobbin case before I was going to bid. The photos are really degraded, but the latch on the bobbin case looks funny, like it may be missing. A new bobbin case will set you back $30-$50 for an original one. So, asking for a better photo would be a good idea.