No, even personal meeting is not necessary, although it is pleasant and useful. Provided you are able to communicate your requirements in an email and agree to a final web design sent in the document in email nothing prevents you from using the services from the side of the globe.
The cost for both the new and existing website depends on the number of pages and the extent of necessary changes. The requirement analysis and web design is time demanding for the new website, existing sites often require partial redesign, especially because of search engine optimization.
Another factor that influences the cost is a number of requirements. High quality websites are not complex with excessive flashy animations , but the pages that are on top positions in search engine results and the visitors quickly find the information they were looking for.
In Czech and in English. It is possible to create web pages in other languages, nevertheless the text has to be completely provided by the customer, including its final position on the page and there is no check after development is completed whether the web page makes sense in that language.