My husband accepted a job with Amazon and he will work from home three weeks a month and from Seattle (Amazon HQ) for one week a month. He needs a place to live for 5 or 6 nights each month, walking distance or a short bus ride to Amazon HQ (6th Ave and Blanchard Street). He does not need major amenities, like a gym or a full kitchen, but he does want his own bedroom. A shared living room and shared bathroom are fine. We’ve been searching hostels and Airbnb, but they seem to be a bit expensive for the private bedroom option. He's looking for something around $40-80/night. He does not have a car or need to worry about parking. Thank you!

The HI hostel on King St. (former American Hotel) is the best you will find. It is within walking distance of the Amtrak King St. station. If it is less than $70/night for a private room it is a dive. I stayed 1 night in the hostel in Belltown after spending more than an hour looking for a parking spot. It was a dive but was the only available cheap room for that night.
The College Inn is an old style European hotel in the north end of the city. It is 1 block from a bus stop served by buses 70,71,72 and 73.

Is this an ongoing situation or temporary? I think you're going to need to adjust your expectations on budget or else look at the hostel options. Prices for accommodation in Seattle, be it hotels, Airbnb, apartments, whatever - are very high and show no signs of going down.

How long is this arrangement going to last? Are we talking 6 months? A year? Or permanently? Does Amazon have a housing office?

For short-term to get started I'd look at: Belltown Inn, City Hostel, The Ace Hotel, The Moore Hotel - to get a realistic idea of what rooms rates even at budget places are like. These four are relatively convenient to the address you mentioned.

This will be for one year... I may need to adjust my expectations...

I'm thinking once he is working in Seattle he might meet people and be able to work something out in a shared housing situation? I'm sure his arrangements are not uncommon at Amazon.

Maybe you could book Belltown Inn ($109 + taxes) which is a 5-10 min. walk to 6th & Blanchard which could at least get him started.

Thank you so much everyone! I really appreciate it. It at least gets us started.

Unfortunately any prices you see for accommodation now are going to spike - as much as 100% - 200% - once the summer cruise and tourist season arrives. The Belltown Inn, for example, goes from $94 now to $269 in mid-June.

The trouble with the Hostel idea is that they almost always have stay limits. They won’t be amused if he shows up like clockwork for a year. The other issue is that your budget is just unrealistic.

I think this might be a good Airbnb situation, although again, budget is an issue.

I do think once he is here and 'networks' on the ground with his co-workers, makes friends, and so on... he will be able to find something suited to his situation. Yes maybe airBnB or with great care even Craigs List.

What we're mentioning here, even the hostels, are for visitors and tourists, not what is really set up for what in reality will be a temporary, part-time resident.

Good point Gardyloo about the summer rate spikes (thanks) I priced the Belltown in for this month.