[dirtywick]

Your way works too and I use it quite frequently.

It does waste a turn and gems if you don't find anything. But moving to the site and searching manually takes at least two turns at no cost. Basically, it's a tradeoff between gems and time.

But, here's a good scenario when spells are better: You have a dormant pretender with Death magic, but death magic isn't available to the nation so your pretender is the only one with a chance of finding it when it wakes up. Rather than moving and searching manually, you can cast spells from afar and find them twice as fast. Then, your pretender is already at a lab and ready to do what you needed the gems for.

It has it's uses IMO.