Interesting tool, Joris! I was looking for something like this for a while. Waiting for you to add London!
Also, I had no idea that flights data is expensive. Is it expensive to buy from the data aggregators? Can you fetch it directly from the airline website?
Cool idea! I've found myself with wanderlust on occasional weekends and it was so difficult to find flights without a specific destination. I think the only missing piece for me would be price, or a link to book (maybe you could do commissions?) so I wouldn't need to look each one up separately.
it's really cool, sometimes I also feel the same for going some random but good places. One suggestions also add a feature of adding journey mate. So that those who are going there can send request for it. waiting for it to over Indian airlines.