djazz

All the horns mentioned above are good enough to play professionally in casual settings. A good vintage horn, even if it was marketed as a student horn may serve you well.

I have found that later Olds Ambassadors play well. I actually like them better than the older ones. A bit brassier and tighter slots. It is all a matter of personal taste and every vintage horn is a bit different.

The Holton Collegiate is good and really cheap. I also have found the King Cleveland and the later 602 to just as good and may be a bit better than the Holton Collegiate.

I think the most underrated horn is the Reynolds. I have two of the later Medalist cornets that are large bore and play really well. Currently they are my favorites but they may be too dark for some players.

A 1960s or 1970s cornet will be cheaper as it lacks collector's value but can be a better bet as it will likely have better valves and less rot. A safe buy is a clean Olds Ambassador.

This is a good time to shop for horns on eBay. Prices are high in the fall but lately I've seen several decent horns go for under $50. At that price it would hard to make a mistake.

Hope this rambling post offers some help. Have fun!