Actually that would make it a 1927 I guess. And, yes, Chu played a transitional not a New Wonder II.

It looks like a deal at $750.  The price reflects the fact that it is a relacquer, which makes the horn less valuable than an original finish horn.  Buffing during a relacquer has potential to damage tonehole rims and mechanical clearances in keywork.  That said, the horn does not appear to be excessively buffed - the fine lines in the bell design are still distinct.  I did not detect anomalies on the tone hole rims that would suggest major buffing damage in the photos.  The horn does not show evidence of major dent work.  If tonehole work is required it would be expensive because of the rolled tone holes (a job for someone experienced with old Conns), but still reasonable in terms of market value if the purchase price is $750.  It might be worthwhile asking the seller about recent maintenance work and if the true of the tone holes has been ascertained. 

The Chu keywork might take some getting used to, but they're great sounding horns.  Lester Young's horn on all those classic Basie recordings was a Chu.