I have seen prices that range from $40 for two (a guy in South Lake Tahoe) to over $200 (on TheSamba by a person in Ventura). New rear drums for the early bus are $85 each at ISPWest, but they are likely to be of "offshore" manufacture. The ISP drums may be of Brazilian origin. They are probably OK, but I would be concerned with the metal quality if they were from China.
The $200 price sounds high, and the $40 price is probably too good to be true.