The best way to figure out this horn is the get the actual serial number from the horn.  Here is an example of the serial no. for a 200 Series model:

Chateau VCH-221(made in Vietnam)

The series 200 does look to be a student model like you stated.  In general, most people looking for used student model horns go with a Yamaha YAS-23 or -21 or one of the versions they made for Vito as a stencil horn (see example in link:  https://www.junkdude.com/collections/saxophones/products/yamaha-vito-student-alto-saxophone

The known advantages to the Yamaha and subsequent Vito version are:
1.  Ruggedness and durability
2.  Large availablity of parts
3.  Techs are very familiar with these horns.

I have nothing against the student level Chateau, it's just that, as you have noted, it is difficult to find information about their student level horns.  If this were a pro grade Chateau, I would give a different answer.