I used to purchase on eBay until I read about scrappers. The majority of the pins I received were scrappers and it sucked.

Fortunately, there is a period with which to do a chargeback through PayPal (shouldn't do this often).
Even if you limit your search to located in the US only, many sellers will say they are in the US but when you get your package, you get it from overseas.
There used to be a board (not disboards) that explained scrappers VERY well. I don't know if we can advertise other boards, but there is also a trading board as well.
So, now I go to this outlet which sells trader pins near Anaheim and examine the pins very carefully. I can get pins for $1.50 - 2.50 each and be assured that they are real, authentic, official Disney pins.
But I have pins for sale for $2 each (primarily starter sets) so the set usually runs around $14-16 because most starter sets have 7-8 pins. You can send me a message if you'd like, through Yahoo (same user id with the underscore) at yahoo dot com. Shipping is free if you order more than $60 worth of pins.
One common scrapper is the Pirates of the Caribbean mini characters set. The scrapper Minnie as Elizabeth Swann is missing her eyebrows/eyelashes! There was an ebay seller that sold in lots of 50, but told you that you would be getting 5 sets of 10 pins (duplicates). A friend got them, they looked fine, and then we went to the store and saw the difference (colors are different, etc.)
Usually, you have to find a seller who only has 1-3 of those sets/lots and they aren't the same types of pins. And scrappers aren't always noticeable. Some have dips in paint, but many do not (like the POTC set).