There are no star ratings standards in the US, well, at least not like Europe, so companies like Priceline can rate properties just about anything they want to. That's not to mean they're completely arbitrary, stars are given based on hotel amenities and services. I just checked, and Priceline lists that property as a 5 star property, so you got what you paid for.

The time to research how opaque websites work is BEFORE you bid on travel, not after. There's lots of resources out there that help with bidding, including the stickie at the top of this forum.