salvage o matic?

whats the difference between runecrafter vs silver fed? seem runecrafter is better 20% vs 25% rare but cost half??

Runecrafter: "Double-click to salvage crafting materials from an item in your inventory. 20% chance of rarer materials. 100% chance of salvaging upgrades."

Silver-fed: "Double-click to salvage crafting materials from an item in your inventory. 25% chance of rarer materials. 80% chance of salvaging upgrades."

https://en-forum.guildwars2.com/discussion/88652/runecrafters-vs-silver-fed

Make sure you read the follow-up responses and links as well.

Which of these two is more cost-effective highly depends on TP prices. The general rule of thumb is this:

• Runecrafter is better for green gear and yellow gear below level 68 because you get more symbols and charms from upgrades (runes and sigils) salvage.
• Silver-fed is better for yellow gear above level 68 and exotic gear since it produces more ectos.