My personal experience with coupons and or promo codes is that if you email them directly and ask for one, they'll usually hook you up.
I do this anytime I'm about to place a large order and 9 out of 10 times they email me back with a coupon code to save a little money.
So, my suggestion is to email them, tell them you're about to make a large purchase, and ask if they have any active promo codes you could use. If they value their customer service they'll almost always give you one.
This is of course assuming there's enough money to be made with the MSRP and the actual price they get them for wholesale.