Hmmm, the 500-1500 might be a tad optimistic. I have the Kermit from this line and mine was actually won at a fair - though I've seen them occasionally get around $50-$100 on eBay. I also saw the Fozzie one recently in a skip.
I agree with FoxWorthy and think eBay is the best bet too as everything is only worth as much as people are willing to pay.
Good luck!