A few questions before purchasing a W3J.

Asus tends to be pretty good with warrantee RMA stuff. For instance, if you're in the US, the total turnaround time between calling Asus to set up an RMA and getting your notebook back should be between 1 and 3 weeks, depending on the issue. And extending the warrantee is up to you. If you plan to be changing out the processor or some other messing around with your computer guts before a year is up, then it's not worth it, as by messing with the CPU, you void the warrantee. But otherwise, go for it if you want a little extra security coverage.

According to GenTechPC, adding in another memory module won't mess up the warrantee at all, and memory is very easy to install. However, if you did want to get it customized, the main disadvantage of a reseller's warrantee to Asus' warrantee is that it wouldn't be global. Asus has repair facilities all over the world, while your reseller most likely only has one.

As to your discount question, both Apple and IBM overprice their notebooks so much that they can afford to give big discounts to some groups. Asus prices their notebooks more reasonably and they have an absolute price point that ensemble models must sell for and an absolute number for how much the reseller gets, and the reseller doesn't get that much. For an Asus reseller to cut the price by 5%, they are cutting their profit by at least 50%, so they can't offer really huge discounts without killing themselves financially.