Re: Conn new wonder series 2
If it's from 1923 it's a Series 1, not a Series 2. The most easily recognized feature distinguishing the two is the "nail file" cross-hatching on the G# key of the Series 2. $1500 definitely high for a Series 1 tenor, and even more out of whack for an alto.
There are considerable compromises involved with older horns, mostly about mechanics and ergonomics. Whether or not those compromises are a deal breaker for you is a personal decision. Only you know your own priorities as a player.
Matt Stohrer has some good videos on old Conns in his Repairman's Overview series on Youtube.