For Mangoldt see the following and the papers included in:  
Kommentarband zum Faksimile-Nachdruck der 1863 erschienenen  
Erstausgabe von HANS VON MANGOLDT GRUNDRISS DER  
VOLKSWIRTHSCHAFTSLEHRE, D?sseldorf:

Hennings, K. (1980): The Transition from Classical to Neoclassical  
Economic Theory: Hans von Mangoldt, in: Kyklos, vol. 33.

Mosselmans, H. (2000): The omitted mathematics of Hans von Mangoldt,  
in: Journal of Economic Studies, vol. 27, no. 4/5.

Schneider, E. (1960): Hans von Mangold on Price Theory: A Contribution  
to the History of Mathematical Economics, vol. 28, no. 2.

I am inclined to think that Rau and Roscher were not against the cost  
theory of the English Classical School, making their positions totally  
eclectic concerning the problem of price formation. Especially you can  
find almost anything in Roscher?s textbook of economic theory. Indeed  
he was a great hotchpotch writer.

On the whole S and D theory is not so dominant in the German  
literature in this period. Of course Mangoldt is an exception.

Yukihiro Ikeda