Supposed potential customers like this I think are a can of worms.
Sometimes what they want is to get stuff FREE.
Other times, they think that you are there for their amusement and constant art changes at their whim.
The worst one I ever had was this woman who wanted me to do an airbrushed mural (which I do) on her entire motorcycle........quoted her a price, did a mass of sketches and got them approved (uhuh) THEN, after the approval, she started with changes......."Oh, let me see what it looks like with these characters" "Oh, I had an idea for doing this, draw up those new designs.......hmmm, now how about......."
Thankfully, I had gotten a sizable down payment.... I told her that she had blown through all of that with all these changes and additional concepts, etc and that any further changes would incur more money. I did, however, tell her that if she made no other changes, that I would do the job as quoted.......
It ended up that for months, yes months, she would call me, going on for an hour at a time that she had talked with her friends and they said for X dollars she should have a mural, not just sketches...........well, I kept telling her, with each phone call....that that would have been the case if she didn't keep making all these major requests for my art time............
long story short, ok, kinda..... I kept everything related, because I really thought that this would end up in court, but FINALLY she stopped calling.
On top of everything else, she was having a custom motorcycle built out of state that I had to tell her that I thought something didn't seem right in all the delays and excuses that they were giving her...........turned out I was right.........they took her money and ran.
ahhhh, she had some bad karma going on there............