Yeah just keep an eye on the refurb website.
From owning both, if you want to save a couple bucks and can due without the better graphics, you should consider a 2009 Mac Mini as well.
It's actually quieter (mine is anyway), and will seem just as fast as a new one, except in games of course.
Many people (including me) also prefer the styling of the older one. Though by volume they take up the same space, the older one definitely looks smaller and better proportioned.
Even though sometimes I miss the 320m in the 2010 Mini, I feel overall much happier with my 2009 Mini. Also, I've known a lot more people with 2010 Mini's that have died than older generations. I feel like that in squishing the Mini down a half inch, they also hurt airflow. I've known 3 people that have gotten the 2010 to overheat, and another one also had a failed hard drive (which is what mine died from). Haven't heard any stories of the like about the 2009.
That said, get what you want, I just wanted to share my experience with you.
The 2.53 should run you 30-50 dollars less than a 2.4 2010 and the 2.26 can run you even less.