Unfortunately, photoshop cs will not work on mavericks, because mavericks does not have Rosetta like snow leopard did.
(no, Rosetta can not be installed on mavericks)
So you need a native intel version of photoshop for mavericks: cs3 thru cc 2014
The current versions offered from adobe are photoshop cs6 if you want a perpetual license or photoshop cc 2014 that is a subscription
This really blows, considering I'm a not-so-recently laid off college student (I had a trip out of the country last month, so most places weren't willing to hire me knowing I'd immediately need a month off). You'd think that because you paid for something you have the right to use it. If I had loads of money to buy a new Photoshop, that would be great... at this point, my option is to downgrade to Snow Leopard. =\
It's not that your not entitled to use photoshop cs forever, but apple moves on and adobe can't be expected to update past versions of photoshop to accommodate new operating systems.
The best of luck to you with your job search.