The scrapping would only be a pretext for C&D. The real reason is the loss of revenue that you’re causing.
Think of it - a hotel got a reservation for say $150/night. Then - due to your actions - the reservation is cancelled and re-opened at $120/night. That is $30 loss right away. The hotel would be pissed off, and express their unhappiness to Booking. Booking would send you C&D - formally because you’re violating the Terms of Services, really - because you impact the revenues.
I believe you’re not taking it seriously.
You have spent 1.5 months building it. Then you’ll spend a year or so promoting it. Then - just when you “have some traction”, you’ll have to scrape it off and shut everything down - or be sued.
You do not value the time you’ve and will put into it?
I bet you’re not the only one trying to do arbitrage on hotel prices. I bet Booking has a watchdog looking for folks like you - because you cost their customers (and them) money. If you continue you activities, I bet you’ll be spotted and shut down.
Booking, however, has an API. If you try and use that, and if the API terms of service doesn’t prohibit the arbitrage (it may) - then you can run your service legally. A bit less profitably, but more safely in the long run.
I just read Using the API. They do not mention arbitration. I’m sure you can use the service in a different way - totally legally, IMHO (IANAL) - mark a room for a user, watch it and book it when the price gone down below N.
Anyway, good luck. I may use your service this summer - if they did not shutdown you yet.