You can put it up for sale in the 'for sale' section here for starters. We LOVE low mileage well kept SRT6's... $15k to $18k seems to be common? Some as low as $12k - $14k.

I would start at $20k on AutoTrader or one of those sites and see what offers you get. If you have no urgent need to move it you may get a better price.

I sold one of my SRT6's through AutoTrader this time last year for $18k. Perfect condition with about 15k miles. I listed it at $20k but needed to move it as I was jobless (and still am) .