When booking a stay with IHG, you can add a points package and buy 1,000-5,000 points per night. These points count as elite qualifying points, which means buying enough of them can directly help you earn elite status faster. The downside is that this option is only available on flexible rates; discounted room rates are not eligible.
The purchase price is 0.6c/p, which is a bit more expensive than buying points during a 100% bonus promotion.
However, based on reader reports, the price to buy points varies by hotel, and some properties let you buy 5,000 points for as little as $3. So when making a booking, it is worth keeping an eye out for this option—it can be a very good deal.