Through April 30, 2013, Starwood is offering up to a 25% discount on the purchase of Starpoints, as follows:
• Buy 500–6,500 Starpoints: SAVE 15%
• Buy 7,000–12,500 Starpoints: SAVE 20%
• Buy 13,000–20,000 Starpoints: SAVE 25%
The normal cost per purchased Starpoint is 3.5 cents, so through this promotion you can purchase up to 20,000 Starpoints at a discounted rate of $525, which is 2.625 cents per Starpoint. You can only purchase a maximum of 20,000 Starpoints per account per calendar year, though keep in mind you can transfer Starpoints between accounts in the same household (though they make you prove you live in the same household nowadays, so you can’t play games) if you’d like to go beyond that limit.
Is this a cost at which I’d speculatively purchase Starpoints? Probably not. In some cases it could make sense to do so for hotel redemptions if you have a specific use in mind and the math works out. Also keep in mind that you can transfer Starpoints to dozens of airline partners at a 1:1 ratio, and you get a 25% bonus for every 20,000 Starpoints transferred. That means if you purchase 20,000 Starpoints you can convert them into 25,000 miles, which is 2.1 cents per mile. That’s probably not an amazing deal for most mileage currencies, but there are some cases in which this can make sense. For example, if you want to book an Emirates award through Japan Airlines, they have very few mileage transfer partners other than Starwood. They charge 85,000 miles for roundtrip business class between New York and Dubai on Emirates, so at 2.1 cents per mile, that’s roughly $1,800 for a business class ticket — not bad!
It’s worth noting that Starwood processes points purchases through points.com, so you don’t earn bonus points for credit card purchases as if this were hotel spend.