Find a sax that you really love, not a certain model, but one that you feel very comfortable playing on. I've been useing a Yamaha YAS-21 for about 7 years. I'd love to have a proffessional grade horn, but I can't bring myself to not play the one that I'm using, if that makes sense...
you can pay big money for a horn or get a Bauhaus Walstein or a sax from Paulo Tung at http://justsaxes.com. They both come from the same factory and I know that Pete plays some of the Bauhaus Walstein's because he says so.
I got some from Paulo and have never had or seen better value for money spent.
That way you can have a new horn instead of a used one.