Try to find some of last year's Afterbangs. They're pretty shitty skis, but they'll be cheap, and if you're not using them much, especially only in the park, they'll probably be fine.
The most I've paid for a pair of skis is $180. I've had new Rossi S3's for $180, new Dynastar Troublemakers for $165, new CoreUPT Candide Yards for $160. The deals are out there, you just have to look around a lot to find them.