This is not an easy question to answer, because it ultimately depends on your project. Because everything we build is custom made, we can only confidently answer the question when we have a full understanding of what you need. The better your requirements are articulated, the more accurate the price is.
Do you charge by the hour?
In most cases, we provide a fixed-cost estimate for projects. Rarely do we bill projects by the hour because the costs are not predicatable nor do they offer you the flexibility to save costs. For example, we will discount projects that do not have an aggressive timeline, or increase the cost based on how many people you would like involved in the design process. The choice and flexibility is in your hands.
What programming language do you use?
We are not a development shop, so we don't work in any particular programming language. However, we do have a couple of partners that we work with on projects that involve more than UI/UX work.