Just as an aside, and I'm not sure whether you're still looking, but yes the Westin is the only known 4 star in the Greenville area. I've stayed there recently and it's quite nice. Pricelineing this hotel is a bit finicky though. Be sure to check their actual website to make sure they have rooms available, otherwise you'll be shooting in vain.
Bidded all over the place...started with $50 for 4* downtown, then $45 for a 3* downtown, 35 for a 2.5* downtown, then $35 for a 2* downtown, then added airport and bid at $30, then added conrod-kannapolis at $34 and there we go.