@Linkat,
It's really, really disappointing when that happens.
We had a tar and pitch roof in West Van that needed doing - I got all kinds of quotes - from $1600 - $32,000!!! Guess which one didn't want the job? Yep. People can be a) unreliable (accept job but then not show up), b) liars (misquote you up the ying-yang), and c) scammers (quote for stuff you don't need).
I go to this place I mentioned for maintenance. They wanted to charge me $125 for an oil change on my tiny car. So I bought the oil and filter myself ($35) and asked what they would charge to do it (10 - 15 min) - they said $30. So, I saved $60... the next year, I went in with my stuff and the guy said it was $60 to change the oil. I said, last year it was $30. He looked through something and said, "Oh. Well, it's $34"... same outfit, different guy.