Since the meeting space is not associated with any hotel - no rooms have been blocked for the conference. There are many options nearby.
The distances below are relative to the center of the Seattle Center.
The meeting rooms are on the west edge of the Seattle Center (see #2 on this map).
Inn at Queen Anne from - $111 - 0.2 Miles West
Best Western Executive Inn - from $159 - 0.3 Miles Southeast
Mediterranean Inn - from $141 - 0.3 Miles West
Hampton Inn & Suites Seattle-Downtown - from $179 - 0.3 Miles Northeast
MarQueen Hotel - from $175 - 0.3 Miles Northwest
Travelodge Seattle By The Space Needle - from $105 - 0.3 Miles Southeast
Quality Inn & Suites - from $129 - 0.4 Miles Southeast
Comfort Suites Downtown/Seattle Center - from $139 - 0.4 Miles Northeast
Holiday Inn Express Hotel & Suites SEATTLE-CITY CENTER - from $171 - 0.4 Miles Southeast
Holiday Inn SEATTLE - from $160 - 0.4 Miles Southeast
Homewood Suites Seattle-Downtown - from $188 - 0.4 Miles West
Best Western Loyal Inn - from $144 - 0.5 Miles Southeast
When you get to about 0.6 miles you have reached the Seattle downtown area Southeast of Seattle Center where there are many options..
Low-cost options are:
Green Tortoise Hostel/ ~0.7 mi (downtown - one block from Pike Place Market)/ Summer dorm rates are about $35(with breakfast) / Website
Hotels near the airport - lowest prices are around $60 - it is about a 20 minute taxi ride from the meeting site ($32). Buses are an option - you can plan your trip here (Try Start:SEATAC; End:Seattle Center West)