Dibs - I want to purchase this pin and am ready to pay.
Bump - To comment on a post so that it shows near the top of the group's feed again.
LE - Limited Edition
AP - Artist Proof. Unnumbered from the factory and is not included in the Limited Edition run.
AE - Artist Edition. Let's say that the band has a new pin that's LE 100. The artist may also have an artist edition.
Factory Raw - Usually just a test raw from the factory.
SE - Show edition
Variant - Different color schemes (also called colorways) for the same design.
Waffle - Another term for a raffle.
Drop Price - The price a pin was originally sold for.
D+S - Drop price + shipping.
G&S - The Goods & Services option in PayPal. There is a fee to the seller but the buyer's purchase is protected (i.e. can be refunded).
F&F - The Friends & Family option in PayPal. No fee to the seller, and no fee to the buyer if certain payment methods are used. Buyer has no recourse if the seller does not follow through, so use with caution.