Amsterdam Hostels

There are at least 3 IYHF hostels (typically less party-oriented) as well as private operations with varying policies. Have you also seen www.hostelworld.com?

Hostels in Amsterdam are expensive, and private rooms at hostels as expensive as budget hotels.

We stayed in a boat hostel, the MPS Holland. Small cabin, ensuite, good free breakfast. 10-15 minute walk to train/bus station. Owners were friendly and helpful. Check booking.com for information on this boat and others also.

i like this one for a substantial breakfast included and close to everything:
https://www.stayokay.com/nl/hostel/amsterdam-stadsdoelen

Amsterdam is just plain on the pricier side when it comes to lodging - particularly during peak season. Even the hostels lean towards the more expensive side of the spectrum. It's also a place where you really want to avoid party hostels if you are just looking for a quiet place to sleep. Read reviews on Hostelworld.

Try Cocomama Hostel which ranges from private rooms up to 6 bed dorms and includes breakfast. Good area - right on the border of De Pijp, not far from Albert Cuypmarkt/Heineken Experience. You can walk to Museumplein.

Also, I have not yet stayed at Hotel Not Hotel (it's actually a hostel - but has a lot of private rooms), but I would like to book a night or two here as it got some really good write-ups in a few travel mags and the design is pretty interesting. Cocomama is definitely more centrally located so you may be able to get by with more walking there and cut back on transportation costs within the city, whereas with Hotel Not Hotel, you'll probably want to hop on public transit more. But Hotel Not Hotel is also in a pretty good neighborhood (Oud West) with Foodhallen within walking distance.