There's lots of items to be found in the trials that aren't magical but still have value. Many can be 'traded-in' for XP after a successful trial, in order to improve your abilities. Gold-coins are a common example.

One particular item to look out for is the good old key. There's plenty of locked doors and containers that need them, with some tasty loot (and sometimes less tasty danger) to be found behind or in them.

Some of the more fiendish trials also have the exit portal appear behind a locked door. Now you know. Blame Sykes for that one. All the other Majestic Few do.