After talking to SPG rep:
Birthday rates are not available yet, hopefully will become available for Oct. dates during April /May 2015.

You can book and change w/o penalty to a different rate as date gets closer.
You can cancel w/o penalty up to 6:00pm the night of arrival.

For the moment the current rates at the Westin Stonebriar for a 3 night stay are:
10,000 SPG points per night = 30,000 pts.
Cash & points is $75. per night plus 15,000 SPG points
AARP rate is $214.39 per night (if you stay 3 nights you also get a $50 hotel voucher which can be used towards food & beverage.
AAA rate is $214.39 (but no voucher)

When the birthday rate becomes available it will likely be:
PAY RATES EQUAL TO YOUR BIRTH YEAR
Get your second and third night at rates equal to your birth year. Happy birth year to you.
First night: from $249
Second & third night: rate equals your birth year (Born in 1948? Pay $48.)
Rates will be confirmed at check-in upon presentation of valid ID.
A limited number of rooms may be available at these rates. Blackout dates and other restrictions may apply.
Book online or call 866-716-8108 and mention code NBR.