Gave a reasonable, but low quote. Wrote-out quote in full detail. Started work, midway through asked for another $1500 in order to install "base", which was necessary due to moisture on the existing roof.
Refused to pay extra, citing contract and 35 year guarantee. Installed base anyway, but did sloppy work overall. Rooftop wasn't level-sloped (hills & valleys in the slope), water doesn't drain properly into eave. Drip edge not screwed down.
As I was signing the contract, they were trying to charge my neighbour $800 for cleaning some eavestroughs which they had previously quoted $150 for. she refused to pay also, and they accepted the $150.