In order to receive an accurate quote (both in cost and in lead time), it is important that you ensure the correct number of blind/buried layer sets is selected in the board options on your project page.
For example, if on an 8 layer board you have blind vias from L1-L3, that would be one blind/buried layer set. If you have blind vias from L1-L3 and buried vias from L5-L7, that would be two blind/buried layer sets.
Failure to correctly specify these prior to ordering may result in orders delays and additional charges.