Category 7 - well that's disappointing.

Out of curiosity just did a search on SPG.com for one night, Oct 11, one adult.

St. Regis: Lowest standard rate from €550. Free night 20,000 points. Room size 269-323 sq ft / 25-30 m²

Westin Excelsior: Lowest standard rate from €313. Free night 20,000 points. Room size 323-377 sq ft / 30-35 m²

G-Rough: Lowest standard rate from €344. Free night 30,000 points. Room size 431 sq ft / 40 m²

And FYI, the G-Rough would be considered a three star property by Italian standards (which are based on what the facilites are comprised of, if there's a restaurant, etc), and the St. Regis and Excelsior are classified as luxury five stars.