Amsterdam hotel in Sept - pulling my hair out!
 

There is some convention - must be huge in Amsterdam in Sept. I am having much difficulties finding hotel. Does anyone know of a less well-known hotel that might be available for around 250 Euros or less. (We always stay at the Marriott for convenience, etc.), but when I travel abroad personally, I stay in smaller places - do need internet access in rooms however.

Why not contact the VVV in Amsterdam - http://tinyurl.com/2wwdev and see if they can help you. Or try http://tinyurl.com/2lzr9f.
Otherwise consider staying outside of Amsterdam - in Haarlem maybe?

Have a look at the NH Hotel City Centre. I stayed there in March on a business trip. We have a miserly per diem (which only stretches to about 140 euros for a hotel, and that doesn't get you much in Amsterdam).

The City Centre has small rooms (or, at least mine was quite small) but very functional and very stylish in a clean-lined, minimalist way. My room was very comfortable and I think the hotel was renovated very recently. It wasn't "smack dab central", but it certainly was very close to the centre; I was able to walk to the train station. The hotel indicates that there is an internet connection in the rooms. Service was pleasant and inefficient. Go to www.nh-hotels.com.

However, I don't know your exact travel dates but I did note that there was no availability for a few weekends in September.

Try this one: www.thebridgehotel.nl
Stayed there in March and it was very nice but had many stairs.

We were in Amsterdam last September and had the same problem trying to reserve a hotel room. We thought that it would be mobbed because of the hotel situation, but it wasn't. We stayed at the Canal House, small, charming and convenient and reasonably priced for Amsterdam. We also were able to get one night on Priceline at the Sheraton which was actually wonderful, for about $120, so you might try that option also.

There is an annual convention every Sept around the dates (roughly) 8th-14th of the month. The city does indeed sell out - anything that's left is triple the normal rate.

www.bookings.nl has a lot of listings you can try.

you could also try booking.com I just looked and there are good hotels available throughout sept.plus there are guest reviews too.

I was happy to find rooms at the Ambassade - had to switch dates a bit, but they had room. I was in A'dam for work so I walked down and checked out the rooms - seemed quite nice and the one I looked at faced the canal. I remembered reading on here that the "basement" rooms were icky so I put a request in that I do not want one of those rooms!

I can also recommend the Ambassade if you can get it. On the Herrengracht, easy walk to center attractions, lovely rooms. I had one of those ground floor rooms once, it was fine except for being under the dining room, so I was wakened early. The switched me to a high room. I do not mind a few stairs for the quiet and air provided!

Definitely give them a try.