Stand Up for Yourself and Negotiate (the ROI is amazing!)

Lately I've been frustrated by the high cost of some things.  Most people just pay whatever something costs, but whenever possible I try to negotiate.  The extra time and effort it takes to ask for a better price is often well worth it.  Just this month I've saved $300:

• As you already know, I've been remodeling my kitchen for several months.  I bought countertops at IKEA, and the first step was having someone measure my kitchen.  I thought I was ready for the measurement, but when the first person came to quote the price, he immediately said that my cabinets were not level enough.  He was in my home less than five minutes, and no special equipment was involved.  I even agreed to an appointment time that coincided with the estimator being in my neighborhood.  Since the cabinets weren't level, I was told I would have to pay a trip fee.  I assumed it would be well under $100 based on what an electrician or plumber would charge to diagnose an issue, but the bill from IKEA was $225.  I firmly told the employee at the store that this was not acceptable.  I was willing to pay something, but thought $225 was too much for a 5 minute visit at my house.  When IKEA stood firm, I threatened to pay the $225 fee but cancel the entire remainder of the project.  The employee said she would talk with management and the installer and give me a call.  A few hours later, she called and told me they would waive the entire fee.  I saved $225 where most people wouldn't bother to complain.
• When I signed up to drive for Lyft, I was promised a $50 bonus after my first 20 rides.  For some reason, I never received the bonus.  It took four separate emails over about two months, but my persistence finally paid off, and I was promised the bonus would be applied shortly.
• On the more classic side of negotiating, while we were in Cozumel we walked into town, but were worn out and thinking about taking a taxi the 1.5 miles back to port.  Based on what an Uber would cost here in Tampa, I knew the $8 I was quoted was more than I wanted to pay.  I had to ask three drivers, but I finally found one willing to take us for $5... but only after walking away did the driver beep his horn and tell us to get in.

Be honest.  Be firm.  Know what you will do next.  That's all it takes to score a better price.  At IKEA, the employee told me that because I did not cause a scene and was professional with my concerns, they appreciated that I was standing on principles and that was the reason that they helped me.  I didn't raise my voice or try to lie about why the estimator had to make a second visit.  I just calmly stated that the price was too high (and swallowed my pride by admitting I made the mistake by not leveling the cabinets properly).

Have you had success with negotiating the price of something or with complaining about an unfair situation?  What was the outcome?