Supplies collectors

Best value overview
For most types of trophies (especiall quest rewards), there are multiple collectors requiring it, each collector may require a different quota for reward. Generally speaking, the collector requiring a greater quantity of a given trophy offers rewards significantly more valuable than his "competitors".

Rare crafting materials and scrolls
Remember to always double check with the Rare Material Trader and Rare Scroll Trader to see the actual market value of their rewards, and compare it with other available rewards (such as the Superior Salvage Kit). Rare crafting materials especially have a tendency to have a significantly higher market value than their merchant value.

Salvage
Each Superior Salvage Kit is worth 4 Expert Salvage Kits in terms of the number of uses, but requires less than double the trophy quota to acquire (when it's available). Whether you consider Superior Salvage Kit's actual merchant value or the equivalent cost in gold using Expert Salvage Kits, it still provides the best possible value out of almost all other available collector rewards (with the exception of rewards whose value fluctuate with supply and demand).

Identification
While Superior Identification Kits provide better value than Identification Kits in terms of collector quota (just like salvage kits), wherever Superior Identification Kits are available as reward, so is Superior Salvage Kits; and Superior Salvage Kits actually provide better value. On the other hand, certain trophies have no better use than to be traded for Identification Kits.