LOL! Make that two dozen!

In all honesty here's a bit of background so that you understand why I do what I do and how I go about doing it.
- I am Canadian. I have to deal with different duties, taxes and regulations than 'mericans. In general, things are much simpler in the US.
- My professional background is in retail systems and processes. Ever since I was in college I've worked at the head offices of various retailers throughout North America so I understand the full process at a grand scale of purchasing, importing, receiving, shipping and retail accounting.
- I enjoy my Ebay hobby but I'm weird that way. I previously started an online venture with a buddy selling spark plugs (free plug to http://clubplug.net, pun intended). I have since left that venture to pursue other projects but it's still going strong.
- I took the 'complicated' approach to doing what I do simply because I enjoy it. What that means is that I have myself set up to write purchase orders, I have a customs broker, etc. even though the volume I generate doesn't truly justify those systems but this falls back to the whole 'I-enjoy-this-as-a-hobby-in-a-weird-way.'

So, some thoughts I'd like to share with you:
- Don't expect to make a lot of money. If you choose your products incorrectly you may actually lose money. What you hope to do is pick enough variety that the winners off-set the losers. My personal goal is to have enough winners that the profits pay for my bike gear.
- Ebay requires customer service and constant attention while you are selling. Your reputation is key and as you generate the right momentum, your customer base will grow as will public perception of you. What this means is that in the beginning you can sort of expect to sell at a lower margin.
- Avoid sitting on inventory. Your garage or basement is not a bank. Inventory sitting there is money that is not working for you.
- Try to pick a commodity product that is in demand and that has few vendors. This means doing research across all channels (LBSes, online vendors, Ebay, etc.) and see what the going price is. You may make money by picking up a niche product but what you want is a lot people bidding your item up, not 1 or 2.
- Don't even think you'll come close to getting MSRP or full retail on Ebay. Look at pricing history to determine what you will likely make and work your way backwards to an acceptable cost price.
- Find a good vendor. My vendors are overseas in Asia. I deal with agents that do contract manufacturing selling generic no-name products and have dealt with grey market vendors. I have never sold used stuff so I can't help you there.

Good luck.