I totally agree with Mart. Over here in the UK you can get free pre-auction valuations, either by taking the item to the auction house or e-mailing photographs to them. This is only my opinion, but I see ebay as a market place that favors the buyers and not necessarily the sellers, and you won't necessarily get any useful information from the punters if it means that they could lose out on a bargain.
If I want to sell any high value items I will always do it privately or through a local auction, making sure that I have a good reserve on it. I would also opt for a local auction house with on-line catalogues as they can and do attract buyers from all over the globe, they are also cheaper than the major Auction Houses. Two that are local to me reduce the commission charged to only 10% if the hammer price is over £1000. That competes with ebay and you have all the benefits of their knowledge and security of payment.
Even if you end up deciding to pay for a valuation, that alone could save you $$$ if it turns out to be a valuable piece. Right now you are offering it for $999, and if someone bought it, and it turned out to be worth $2000, then that's $1000 lost that could have been saved with a small output of $$ for a proper valuation. Again, JMO.