The advertisements also provide rich material on how the value of a book was determined. A comparison can be made between what the authors planned and demanded as a preliminary price and the amount that was actually received after printing. The price of the editions according to the advertisements was calculated in various currencies - groshen, medzhidiets, talers, shillings, rubles, etc. It usually differed for patrons in the Bulgarian lands and outside them. It is striking that the authors included only the printing costs in the price, without valuing the labor invested. After the sale, they managed, at best, to recoup their expenses and very rarely to make a profit as a reward for their skills and competence. It was not until the mid-19th century that cases began to arise where authors sold their rights to a particular manuscript and the person who bought them assumed the commitment and costs of printing.