Simple solution, Josefek. Call another tile guy. There are "difficult" contractors in every line of home repair, but that doesn't mean that you have to deal with them. Call several and ask them to quote on the job. If they all tell you the same thing, then I would listen. If you ask three contractors to quote, pick the middle bid and let them do the job. If you are sold on doing it yourself, send some money to the one that was most helpful and allowed you to pick his brain the most. That is only fair.
For what it's worth, I deal with many suppliers to contractors. It bothers them too when some guy comes in bragging about how much he was able to rip a customer off since it is bad for the whole industry. So you might start with asking the local tile suppliers who they would suggest to install tile. At the same time, the contractors time is valuable. If not quoting you or allowing you to pick his brain, he could be making money on a job. So compensate him for it.