my mom found 2 of these that I inherited- I've sewn on at least one of them but not for long (was trying out some of her machines about a year ago and have finally gotten back to trying them out again and setting them up for sewing) neither of hers had cams and I went on a 'hunt' - I didn't find them as easy/cheap as the tophats - I managed to find some though between ebay and etsy. seems like I looked up what was made in the flat cams and got the numbers and compared ebay sets- some would be missing certain ones..then picked the best deal for me. I think the 319 and 306 take the same cams but may take some extras- was never sure with these and the top hat cams if all would work or just the numbers listed for that machine...anyways I haven't tried the cams yet but that's in the plans just may be a while - plus need to find where i put them
I think any working machine in decent cabinet is worth at least $50 or even more. as to whether you enjoy sewing with it may be a different story. I remember it being a machine of hers that I DID like and that was after reading not-so-favorable reviews of it being noisy