From their email (and post) announcing the sale (the red is my emphasis):

Quote Originally Posted by Senor Rocky
First, we are about to receive a huge shipment of Argyll Jackets and Vests. We’re getting SO many at such a great price that we’re able to put them on sale for $249.99 for the Jacket & Vest combo (size 38 to 52 ONLY). We FULLY REALIZE that the Jacket alone is on sale for $289.99. We want to make sure you really get your money’s worth when you buy the jacket and vest together! Please note that the jackets are currently clearing US Customs, so they will be ready to ship in about a week. You can PREORDER the jacket and vest on the website now and it will ship as soon as the order clears customs and arrives at our shop.