Rach,
Elna Supermatics are prone to a certain part breaking--can't remember the name. I've avoided them due to this part failure which is an expensive repair. I'm sure others can ellaborate. The Elgin appears to have quite a bit of plastic in it.
Others will disagree but I feel it's better to seek out the sewing machine rather than have it seek out you. If you have a certain job in mind look for a machine that is well known to perform it well. If you collect try to have some kind of focus in mind. To buy anything and everything that is interesting or cheap you'll soon loose room for the good stuff. BTW, I'm guilty of not following my own advice
Jon