Sure. AR (after rebate) means total price we pay after receiving a rebate check back in the mail. We pay the higher price and then have to mail in a form, copy of receipt, and the UPC symbol from the box to get the rebate back. It takes anywhere from 6-10 weeks, and occationally you need to follow up with a phone call to get it. So you have to make photo copies of everything just in case. All this hassle means that many people never go forth and submit the rebate, and that is why they(the manufacterer or store) do it. Many people don't mind mail in rebates like this. Others know they won't mail them in anyway so they ignore the rebate part of the price. Hope that helps.
edit: Here is an example. Our cost is $219.99 + the shipping, plus any tax if you live in the few unlucky states they charge tax in. Then after submitting the rebate form and requirered proofs of purchase, you later get a $20 check in th mail. http://www.newegg.com/Product/Product.aspx?Item=N82E16814127329
This one is $20 cheaper without a rebate hassle. http://www.newegg.com/Product/Product.aspx?Item=N82E16814125089