Did the same thing first weekend we had our BC. Ordered from Heartland at .94 each with Club discount but they nailed me for $15 shipping via USPS. Never again.
Jim, I was quoted the cost of the part; because I knew the part weighed almost nothing I wasn't really concerned about the shipping cost. When I received the padded envelope with the parts via USPS first class I looked at the invoice and there was a $10 shipping/handling charge. I called customer service and asked about this and was told that there is a minimum shipping handling charge of $10 per order.
I didn't argue the issue any further. I haven't placed a parts order since (Oct 2011).