Translation being a customised service by nature, a translator cannot give an estimation – let alone a quotation – before seeing the document. They may give their hourly rate, but how many hours will be necessary still depends on the document.
Clients sometimes assume that the number of pages is enough for a translator to know roughly how much work there is, but the length of the document and that of the text are two very different things: the former will vary greatly depending on the font style and size of the text, the spacing and margins, and whether there are any headings, pictures and footnotes. The text means the content to translate, regardless of any formatting.
Regarding content, each text has its own unique combination of terminology, style, quality of writing, etc. Consequently length is not the only criteria. For instance, a CV is typically short but extremely concise. As it rarely contains full sentences, each word is a keyword and most words are likely to be specific to a particular industry. For this reason, a document such as a CV, despite being short, is quite time-consuming to translate.
In short, asking a translator for a blind quotation is as good as asking how long a piece of string is. If you are keen to get an idea of cost, the translator is equally keen to see the document first because if the text is likely to take much longer than expected, it would be awkward to discuss the price again on seeing the document. Similarly, if the text proves less demanding than average, they would hate to scare you away with a price that could have been lower had they seen the document first.
Avoid surprises: send your document with every quotation request.