Always worth to check the hotel website.
At a hotel in Pattaya : Just managed to book a room category which does not show up or shown as booked on Agoda, Booking.com or Expedia.
Booking though was fairly complicated through Paypal, VISA credit card (VISA secure).
A hell lot of logging in to my banking app, requesting codes bla bla...
Jumping/changing through the websites on the mobile.
But I could pay 2000 Baht deposit from my VISA with proper exchange rate and no fees.