eBay may be the best choice. Watch similar sales for buying trends. I sold my Kit lens fro the Rebel XT. it was worth about $80 retail. they had sold as low as $40 and one even went for $120. I got $80 for mine plus shipping by listing it when there were good bids on others and not many available. In my auctions buyer pays shipping and I pay insurance, always. It's good , ... uh... insurance. heheheheee and it is very cheap. I sold my Minolta X-700 setup all seperatly on ebay. I took the package to a used broker for an esimate. I sold the power autowinder alone for more than he offered for the whole kit. Body, 4 lenses, flash, winder, 10 filters....
But that was 3 years ago, financialy it may be better to donate it or something. Local museum maybe? heheheee
Good luck.
Mikeeee
MIkeeee