Call the sponsor and see what they can do...
I hope Todd from Epiq doesn't mind, but I will give you an example :
I needed a battery maintainer for my Boxster. I usually buy from Performance Products, but since I spend so much time on this forum I thought I should give one of our sponsors a try. PP has it listed for $71.96, Epiq for $74.40. I sent Todd an email asking if he could match their price. What he pointed out and I was not aware of is that Epiq charges $9.90 for shipping ( $84.30 total ) and PP charges $13.95 for shipping ( $85.91 total ). So obviously I went with Epiq.
So, my suggestions when comparing prices is look at the TOTAL cost not just the item cost, and contact the sponsor directly and see if they will work with you...
Just my $0.02
Nick