Hi Larry,
Reading your other post I understand where you come from.
You worry too much, and are trying to plan ahead things that do not need any planning ahead. But if that's you, then me saying you don't need to plan your hotel booking ahead will not work for you, so what to do..?
First of all a decent budget hotel in Kathmandu would set you back US$ 10 to 15 at most. US$ 20 is already an upscale hotel.
Hotels in Kathmandu are notoriously bad in taking advance bookings. They will say they take your reservation, but most have no reservations book. So when you arrive they will have a room only if it happens to be available (90% of the time) but they will sell their last room if they can and never know about your reservation.
If you want to be sure of any pre-booked reservation, then you will have to book an upscale hotel room, and expect to pay cheap to regular western rates.
On the other hand, booking ahead is really not necessary. From the airport you take a taxi to the Thamel area (30 - 45 minutes drive, about US$ 7 or NPR 500). Have yourself dropped of at the 'Kathmandu Guest House' squad in the middle of Thamel and they will have a room for you, whether you have a reservation or not.
(and have nobody tell you it's closed or out of business, for it's not - an old trick where people would like to guide you towards a hotel where they get better commisions).
ktmgh.com/
Probably just outside the airport at the taxi stand there will be people waiting, waiving around signboards with 'Kathmandu Guest House' on it. Talk to them and get a free ride to the hotel. This is a rather upscale place, so expect to pay about US$ 50,= or even more for the first night here. Next day you walk around the Thamel area, and find yourself a less expensive room for the longer stay.
In the Thamel area you can find at least 250 cheap hotels (if not more), and al least 10 upscale hotels and many in between.
Don't worry, it's easy..!
Take care,
Jorge.