Upgrade your RAM, and before you do anything else, back up your hard drive.
If your Mac is the model I'm thinking of, you should be able to upgrade it to 8GB, which will be more than sufficient for Mavericks. What's more, it'll give you a decent boost in Mountain Lion, too. I'm assuming your Mac is a 2010-era model - you can tell us which one it is by going to the Apple menu, selecting About This Mac and then clicking on the More Info... button.
Last edited by Peter Cohen; 08-06-2013 at 12:38 PM.
08-06-2013 12:26 PM