Distribution of a computer program

A computer program is required. The essence of the offer: there is a program that allows you to easily fill in a large number of documents on a template. For example, you need to send 100 or 1000 identical letters to utilities defaulters. A template is written where instead of surnames, sums and addresses, variables enclosed in the # characters are inserted. Separately, a table is created, where a list of all debtors is created, with amounts and addresses. The program processes these two files and outputs 100 or 1000 (how many lines does the table contain) letters with the same content, but different individual data.
The cost of the program is 1000 rubles, payment is possible by bank cards. The intermediary receives 40% of the cost of the program (400 rubles) for a Yandex-money wallet, unfortunately, other forms of payments are not supported yet.
The program is tied to a specific computer after payment. For payment and binding, an Internet connection is necessary. After payment, within an hour, the restrictions of the demo version are removed. From himself, the distributor can offer paid services for training, setting up or developing templates, this is his personal business.