Personally, I would never leave a tip at all, because the photos are still filtered beyond recognition , it rewards their deception and encourages this bad behavior. If Your time and effort was wasted shouldnt you be compensated as well?
I'm not telling anyone to follow my example but for the sake of storytelling:
A couple times I just left while making loud noises to 'wake the neighbors' and frustrate their business which relies on discretion' with other units on the floor.
Once I was so upset at the wasted time/energy/gasoline, I barged in without paying stayed in the living room and told them I would wait until the handlers came to apologize. I knew they wouldnt risk anythibg that would cause police to come, that and Im a big dude not scared of altercations. The SPs left the apartment and the Handler came in after 1 hr and paid me to leave. In comes a computer bookworm (phone call guy?) and an old uncle (Handler/owner) with money in hand asking for me to leave. Don't do as I do , but most of these agencies are not run by Thugs or gangsters at all