> Do you know by any chance what would be the magnitude of costs for licensed databases that would cover the majority of businesses/venues/places in the world (excluding non-touristic countries/cities, e.g N. Korea, Afghanistan, etc.)?
Licensed databases are going to be 'call for price', but you might see if you can get free/low cost feeds from companies that want to sell something: food ordering apps might let you have a list of restaurants if you link the restaurant to their app; you might be able to get a hotel feed from an OTA like Expedia, etc. Maybe Yelp has a feed??
Otherwise, you've got to find data sources and figure out how much they want, or talk to your legal team and build crawlers. I used to work at Yahoo! Travel, and we had a lot of data sources, I can't remember all of them, and was never involved in pricing discussions, but I think we tended to include attribution, if you dig into the internet archive. The base hotel feed came from Sabre, restaurants came from multiple sources (and Y!Local which had its own sources), points of interest and city information came from guide book providers like Fodors and Lonely Planet, and I think a couple others. Ski conditions came from OnTheSnow (which was a pleasure to work with).