I would try Priceline and bid for a four star hotel in the "Seattle Center-Space Needle" area and start around $85. If that doesn't work then add the "Seattle Downtown-Pikes Place" area and up your bid by $10.
If that doesn't work then lower your star level to 3 star and don't raise your bid. I would not recommend going lower than a 2.5 star hotel.
See how that works out.