By the end of my trip to China, I was starting to pick up the ability to walk away. That was a skill I put to use with mixed success in Cairo. On the first day, we were stuck way out of town and our guide mentioned hitting a local mall as something to do within free time. I checked with the travel service at the desk about getting a ride their and back and their price was nowhere close to the $4-5 each way that my guide had mentioned. I got them down from 300 (~$50) Egyptian to 150 Egyptian (~$25) and was offering 100 Egyptian ($17) which was probably still too high but an acceptable markup for something to do. They told me to go talk to the taxis outside, and we failed to reach an agreement.
I'm fairly satisfied with that outcome, although my counter price should have been lower. I think they also may just honestly charge more than my guide thought when it comes to the pickup on the way back. I ended up swimming a bit, prepping my room, and checking out the hotel instead. I also exploited my two paid for meals and skipped getting a lunch. In the Cairo section, I actually overdid it a bit on the free food. By the time I left I was better knew my limits.
I did no other shopping of note in Cairo, sadly my subsequent bargaining experience have been les impressive.