I'd contact B&H first to see if they will give you a refund or credit for the difference. If not, I wouldn't bother returning something for $20 but I would absolutely do it for $150.
From the B&H website:
Extended Holiday Shopping Return Policy!
B&H has a 30-day return policy. For the convenience of our customers who want to begin holiday shopping early, we are extending the policy's time period. Beginning with purchases made November 18, 2012, our return policy will be either until January 18, 2013 or 30 days, whichever is longer. All other standard return policy conditions apply.