The worst customer experience... Once a guy called me and asked for a quote. I told I prefer hourly rate * hours worked and explained why it's better for him. He called me crazy and insisted on fixed quote, although he wasn't even sure what he exactly wants. I did fast calculation in my mind and gave him a rough quote. I was bargaining at that time and quote was really very low. Then client did a fast calculation on his end and was lecturing me for ~ 45 minutes that I'm ridiculously expensive and I won't have any clients unless I lower my prices 3x and how dare I charge average monthly salary (for probably 2+ months work...) if I never went to university and so on..
Fast forward 1.5 years - I charge 4x more than in those days and I'm fully booked...