Obviously there are different Ebay strategies. You can start low with no reserve to get bids going, but you run the risk of having your item sell for peanuts. Setting the reserve too high can scare off bidders (although it keeps the bargain hunters and tire kickers out). I think, though, that a high reserve makes the ad more expensive.
I have sold speakers, amps etc on Ebay and always got a good price. A few "tips" that have helped me:
1) A good ad helps. Use good grammar and double check your spelling. An ad that's incompetantly written will hurt credibility and make you look "shadey."
2) Post some good pictures. Stock photos from manufacturers websites are not a good substitute for images of the actual item up for sale.
3) Always time your auctions so that they expire at times when a lot of people will be watching, like 7:00 PM EST on Fri or Sat nite. Lots of people are on ebay between 7 and 10 in the evening, and most people will set things up to display items ending soonest, and this is the default for things people are bidding on. I've scored some terrific deals when buying simply by watching auctions that ended in the midday or morning early in the week. True, some will set a proxy bid for the max they're willing to spend, but lots of people will only bid towards the end. Especially 'snipers'- those guys will watch items and only bid in the last seconds of an auction to avoid "tipping their hands" and driving up the price.
4) Be straightforward in your dealings. Leave feedback promptly, answer questions ASAP and he honest with your transactions. Good feedback is critical to a sellers, and helps for buyers, too.
5) Lastly, when selling, think long and hard about what the lowest price is you're will to accept. Under most circumstances you're obligated to sell to the winning bidder. If you speakers are worth $500 to you, and you couldn't see going any lower, consider starting your auction at that amount or setting that as the reserve. You can put a pretty tempting "Buy Now" price on them, too- that's often a great tool.
Good luck with whatever route you go.
