I want something strange: are there any services / software for collecting statistics from open sources?

Question

Google

I am interested in the following:
is there any free (open, free, fairly cheap, say up to 5 thousand rubles) software / web services exclusively for personal use, or what needs to be studied in order to figure out the problem yourself:
There is a lot of accessible and open information on the Internet, for example, about the prices of goods, or a list of requirements for vacancies, or publications of interesting authors on various resources. Sometimes it is required (for personal needs, as well as for planning one’s own development) to get an idea of ​​the price / quality / required skills / time spent, for example, analyze vacancies on the topic for which skills how much they pay in the labor market (on average) or track changes in the price of some specific goods (high-tech, software), if only because not all online stores have services for comparing prices with competitors and the option to track the cost over time and discounts.
On the one hand, this formally refers to web analytics, on the other hand, the same web analytics is more interested in conversions and analysis of page visits, rather than parsing content and compiling average reports.
In this connection, I ask you to send me what you need to study / how much to buy such services and solutions

Answer 1

www.similarweb.com