eBay can get you the largest market exposure, BUT there are lots of pitfalls to selling on eBay, and being a new Seller, you may fall victim to some catches that you are not aware of...
#1 Most Buyers use PayPal to pay of items. eBay and PayPal put an automatic holds on all payments to New Sellers for a minimum of two weeks after the money is collected, and until after the Buyer posts Positive FeedBack. The Buyer posting Negative FeedBack on a transaction means that you will never get the money unless/until the FeedBack is retracted by the Buyer. You will be forced to pay for the shipping out of your own pocket, and wait until the money is released.
#2 Do Not Use The eBay Shipping Calculator. While it is convenient, the shipping calculator is often seriously wrong because it does not take into account things like oversize, residential, signature, and odd shape charges added by the shipping company. Bikes are considered to be oversized, and there are additional fees involved. The shipping calculator will collect $40-$50 for shipping based on weight alone, and you will be stuck with another $100-$200 or more in shipping charges.
#3 eBay and PayPal Services cost money. About $15% of the amount collected from the Buyer goes to them. If you figure that something will cost you $50 by FedEx to ship, you need to collect the extra 15% (about $9) from the Buyer to cover your cost. Factor that in.
#4 Don't forget to cover the cost packaging materials and transportation to the shipping company, or the cost of having the shipping company pick the box/es up from you. The LBS around here charge $60 to disassemble and pack a bike into a box.
I would try to get a valuation and then try selling the bike on CL, before trying eBay. Much less hassle, not having to pay for shipping, and then wait to get the money. CL is Cash and Carry. but full of flakes. eBay can have just as many problems. I have a mountain bike for sale right now on eBay, and I've sold it four times, but have not been paid once yet.
I sold a set of new Shimano Ultegra 600 Non-STI brake levers, and the Buyer claimed they were used, then filed a claim against me with eBay, swapped parts on my new levers and sent them back without the original factory packaging. I am out the value of the levers, plus the eBay Fees, and the PayPal Fees. eBay and PayPal are rigged in the Buyers favor now, Sellers can't even post Negative FeedBack when they get ripped-off by Buyers. And it looks like the previous Seller Protection Plan to reimburse Sellers when they are defrauded by Buyers is no-longer in effect. eBay is Seller Beware/Seller Hostile.