I've bought over 200 items on e bay over the years, not had much trouble, apart from being caught by customs charges, when I imported stuff from the US
best bike related items are the two heated jackets at £40 and £36 for the second one
One thing to be aware of when selling valuable electrical items is , to check the serial number of the item even take a video clip of it working, As ther are people out there who would repair theirs with yours, and then ask for a refund