Bought a lens last week from B+H and now it is $100 less than what I paid for it on their site. It's not even here yet. If I contact B+H, are they good about issuing a gift certificate or store credit for the $100 difference? (i bought it with a B+H gift certificate). Or do I have to do a RMA and physically send the item back? Thanks in advance, looking for some guidance before I call tomorrow.