I know this is a bit over your budget, but you are getting some added perks that perhaps will justify the rate:
For $550 you can book the American Express FHR rate at the Ritz Boston Common (assuming you have an AMEX Platinum Card). That gets you a large Executive Suite (Bedroom and french doors to a small living room - total size about 550 sq feet), with a chance to upgrade on check-in to a much larger Luxury Suite. The rate also includes the following perks - the 4pm checkout in particular can be a big plus:
THE 2006 PROGRAM INCLUDES THE FOLLOWING AMENITIES
*UPGRADE AT CHECK-IN BASED UPON AVAILABILITY TO A LUXURY
SUITE
*COMPLIMENTARY CONTINENTAL BREAKFAST FOR 2 DAILY IN JERNE
RESTAURANT AND BAR OR THROUGH IN ROOM DINING
*BREAKFAST WILL NOT BE CREDITED IF UNUSED AND DOES NOT INCLUDE
GRATUITY
*GUARANTEED 4 00PM CHECK OUT
*LUNCH FOR 2 IN JERNE RESTAURANT AND BAR EXCLUSIVE OF BEVERAGES,
TAXES AND GRATUITIES ONCE DURING GUEST STAY.
*FHR&S WELCOME CARD TO BE PRESENTED AT CHECK IN
Without the Platinum card you could book there Special Occasion Package for $695/nt which includes the following:
SPECIAL OCCASION PACKAGE
INCLUDES DELUXE OVERNIGHT ACCOMMODATIONS IN AN EXECUTIVE SUITE
WITH SEPARATE BEDROOM & LIVING RM AND 1 1/2 BATH
AMERICAN BREAKFAST FOR 2 THROUGH ROOM SERVICE OR
JER-NE RESTAURANT
CHAMPAGNE AND FRESH FRUIT
OVERNIGHT VALET PARKING
ROOM TAX NOT INCLUDED
THIS PACKAGE REPRESENTS A 20 PERCENT VALUE OFF THE REGULAR
RETAIL PRICE
(Other than parking and full breakfast instead of continental, the extra $145 is not getting you much, and you lose the upghrade, 4pm checkout and lunch).
The same package is offered at the original Ritz (and your suite will have a wood burning fireplace).
As for your original question - the Four Seasons is the top hotel in Boston, and the service is exceptional. The rooms are lovely - but certainly not remarkable; but the entire hotel is top notch. The Parker House has a far inferior level of service, and other than some lovely common areas, it is far from memorable. I have not seen the suites there.
The Four Seasons does have a weekend rate in September of $595 for an executive suite.