From experience doing something similar, you may find you actually get better participation rates if you give away doughnuts or canned drinks or something, for the following reasons:
People are more familiar with the idea of a product give-away.
The physical things are visible and draw attention.
The reward is more tangible/exciting than straight money (especially if you are considering lower values like $1 or $2.
In terms of benefits to you:
Less paperwork/liability for you than giving cash to strangers, and cheaper, as you’ve mentioned.
For some reason this is just hilarious to me. I can’t help but anthropomorphise Golden Gate Claude and imagine someone who is just really excited about the Golden Gate bridge and can’t stop talking about it, or has been paid a lot of money to unrepentently shill for a very specific tourist attraction.