Where are the cheapest places to park in downtown Portland (that doesn’t use Passport)

I’m at the age where if I can’t find parking after circling the area twice, I’m going home. Last night, I drove into town to meet a friend for dinner but all the street parking was taken so I ended up using a parking garage (vs a private lot) which cost $8/hr. Town parking which is paid for via the Passport parking app is much cheaper but there weren’t any available spaces in the vicinity I was looking for. I almost parked in a privately owned / operated lot but it was just over the garage price. How in the hell is parking so expensive?? This is deterring people from supporting restaurants and small businesses. The fact i ended up paying $16 for parking just to have a 1.5hr meal is wild to me. That money could’ve been used to buy an appetizer or give a larger tip. 😤