No. The prices you see on this site are what you'll be charged at minimum for the service selected. The final price you'll be quoted will factor in other variables like project complexity, project value, deadline(s), etc. All of which will be explained before entering into any official agreement.
During the discovery phase (where I inquire as to the nature of both your business and the goals you want to meet), I do my best to make sure that we are on the same page before we move forward. Nothing I produce at any point will take you by surprise.
However, if you feel that the project is not going the way you envisioned, we can end the agreement, I turn over all materials produced up to that point, no harm no foul.
But if you wait until the waning moments/deadline is near, or the final product is completed to say "I don't like it," you will still be charged the remaining amount of our contracted deal.
(All this supposes that you have officially entered into a contract with me and have paid the required retainer.)
That depends mostly on the complexity of the site, the urgency of the project and the deadline set during negotiations. On average, it takes between 2 - 3 weeks.
Payment usually comes in halves. Half upfront (which serves as retainer), and the rest is due upon project completion.
Assuming we have entered an official agreement, a retainer is needed. The retainer, depending on the agreement, ranges between 25% - 50% of the total value of the project.
If we have not, then we need to have a discussion about the project and as many details as possible, so that I can accurately quote you for the task at hand.
If, after we have come to an agreement, you discover/find that you need additional services, we can come to an arrangement on a case-by-case basis.