overstock broker,
To stock more of (something) than necessary or desirable.
n. (vr-stk)
An excessive supply.

字面意思为“过剩商品经纪商”，他们以低廉的价格从大卖场以批发价格购入大卖场滞销的产品，再以比原大卖场低廉的价格将货物出售给消费者。但是，如果使用上述翻译，华人读者也许会认为这些商品质量差或者过时了。也许可以考虑改为：

转手货品店/转手经销商(overstock broker)

salvage broker
字面意思为“商品拯救经纪商”， 可考虑译为“退货转售商(salvage broker)”，定义如下：
http://www.amerisurplus.com/salvage.htm

Retail store chains need an outlet for their merchandise that they can't sell in their store- so instead of trying to sell it retail, some sell it out to wholesale dealers as salvage. Salvage merchandise is merchandise that has been exchanged, returned, or shelf-pulled for any reason. It is sold "as is" and loads could consist of:

New Merchandise
Clearanced Merchandise
Returned Merchandise
Shelf Pull Merchandise


--------------------------------------------------
Note added at 6 hrs (2011-12-04 20:08:32 GMT)
--------------------------------------------------

overstock的货物是指第一级商店进货太多了而无法消化的商品，因此这一级的商店会以低于进货价的价格批发给overstock BROKER，后者再以低于大卖场的零售价的价格出售给消费者，因此有点像“清仓处理”。overstock broker经营的货物都是从大卖场进货的新货物。


salvage broker除了从事与overstock BROKER完全一样的业务外，还经营Returned Merchandise 和refurbished产品。

所以，两者虽在经营SCOPE上有点差别，但本质上是一样的，都是从大商店批发来货物转卖给消费者。


--------------------------------------------------
Note added at 6 hrs (2011-12-04 20:10:10 GMT)
--------------------------------------------------

都属于清仓货物折价中心。