Ebay offers mixed results, but it's often so much cheaper than the internet dealers mentioned above that you can write off the mistakes and still be way ahead of the game.
Or just stick to Ebay sellers that have high feedback scores and good return policies. Three that I'd say you can't go wrong with are:
Meangene5 (feedback of 5683, 99.8% positive)
scottcampbelllps (feedback of 3328, 99.9% positive)
kevinarmy (feedback of 3400, 100% positive)
An important bit of advice about buying on Ebay:
On Ebay (assuming at least 100 transactions as history), if a seller has less than 98.5% Positive feedback, I stay away. Less than 98% is a bad sign. It may sounds paranoid, but you have to realize that most Buyers are afraid to leave Negatives for fear of retaliation by the Seller, who often withholds leaving feedback until the Buyer has done so - ESPECIALLY if they know the item they sold is not so great.
As can be seen by the track record of the sellers I listed above - outside of the occasional random mistake that we all make, there is little excuse for accumulating Negatives. In my mind, a seller that has 98% is probably running more like only 70% of customers truly happy with their purchases. A seller with less than 97% is generally a complete disaster.
Hope this helps.
