I'm a fan of using portals like AA E-shopping and United Plus Shopping when I purchase products from Loews, Home Depot, Zoro Etc. It's also a great way to extend miles when they are about to expire.

One one thing I struggle with is how to determine if I'm better off a paying a little more to get the points or choose the better price and forgo the miles. An recent example is Zoro has a product that sells for 117.00 including tax. Double points form Zoro will net me about 220 points. I am able to purchase the same product on eBay for 98.00 with free shipping and no tax.

My question is what is the value of 220 points? I have done the math but am not 100 percent sure it is correct.

Thnaks