Valuing my TV for re-sale?

I currently own a 42" Panasonic Viera Plasma model TH-42PZ8OU. It's a few years old, but is in excellent condition.

Is there any way to estimate the value if I want to sell it to someone else? I don't want to overcharge someone but I don't want to screw myself either.

Years? So you're interested in selling an antique?

Well take your original price and then take about 75-80% of that and that's a good asking price that someone will bite on