Downloading and monitoring of prices in the service with offers of travel agencies

I will commission a scraper in PHP that:

- will download all vacation offers from: wakacje.pl/wczasy (note, the service only throws out the first 1000 results (10 per page and 100 sub-pages), In fact, the service contains about 30,000 different offers and I would like to get all these offers,

- will monitor the price changes of all these offers, and if the price changes, an annotation in the database is needed (and if some offer is removed from the parent service, also need to remove such offer from the database). Ordinarily, if new offers appear on the aforementioned site - you also need to add them to the database and then let them into the queue for price checking.

Basically, that's it.

Please give me price quotes and completion time. I care that it should be created in PHP.