A bunch of months ago, Bestbuy had these wheel kits on supersale for $149, but they sold out and never restocked. This $139 price is best I have found in a year. Expensive yes, but best price available...yup-yup.
You can easily bash high-end coolers, but if you are one of the millions who like them...I have compared-and-contrasted multiple brands and hugely recommend what Otterbox is doing with their new product line. VERY innovative. VERY well designed and overbuilt. Different is not always better...but in Otterboxes' case it is.
(I do not work for Otterbox, but I do own a small manufacturing co. My business succeeds because of my happy customer recommendations...I pay this referral-thing forward whenever I can.)