Recently...
Previous client, on quote for new project: I know that this is completely simple and will take you less than an hour, how can you try to charge me that much?
Me: It will take around 8-12 hours.
Previous client: No way! Why are you trying to ruin this relationship and rip me off?
Me: It is because of our previous working relationship that I am quoting you this low rate, I am in no way trying to rip you off - tell you what, I'll throw in the logo since it's loosely based on the previous project for free but the quote remains the same.
Previous client: Okay I'll go with your quote. I also want you to create 4 new images for the front page.
Me: This will cost you another $xxx.
Previous client: That's a joke right? I know it only takes 10 minutes to create each image in Photoshop.
Me: Have you got Photoshop?
Ex client: Yes.
Me: Excellent, good luck with that then.
A potential client, having been supplied with a complete list of relevant experience: This will only take you 30 minutes, how much will you charge.
Me: It's about 2 hours work - I'm not doing anything else today and it's pretty simple so I'll do it for $25/hour.
Potential client: Can you do the whole thing for $15?
Me: No, $25 is way below my usual rate.
Not so potential client: $20 an hour it is then. Can you provide references for similar projects?
Me: $25/hr is an absolute minimum and I don't want to bother my references for the sake of 2 hours work, I think it's best you find someone else.