When I overnight at AMS, I have always successfully booked via "name your own price" the NH Schipol for around $75 US per night + tax and fees. Negatives about this is that there is little in the way of food nearby. Perhaps the most expensive McDonalds in Europe across the street will please you. Plus the last time, they started charging 5 Euro for the return trip to the airport.
You might also check
www.lastminutetravel.com which sometimes, but not always has astonishing rates in various cities. This is an opaque site, but with a little effort, you can determine with high probability where you will end up. Using a combination of of Expedia and LMT maps and amenity symbols will sometimes yield enough information to pin down the hotel. In the case of AMS, looking at the photos and matching them to Trip Advisor's will tell you for sure where you will be staying. Some photos actually give you a big hint such as the photo of an airport shuttle parked in front of the hotel. On the side of one van is a very large sign stating "Radisson SAS". The van is also parked under a sign reading "Radisson" Obviously this is
not the Hilton van parked in front of the Hilton. A picture of the restaurant sign coupled with a quick Google search will often tell one the name.