Having used both the phones for quiet some time, this is what I have to say.
A brand spanking new Motorola Atrix with unlocking charges (about $20 ), shipping and duty will still cost you around 21-22k. Slightly used ones will be considerable cheaper on ebay. But buying used phones off ebay is very tricky. When they say minor scratches and sometimes thats true, and sometimes those minor scratches and skuffs are not so minor.
So in the end Atrix will be about 3-4k cheaper than Optimus 2x which will carry local warranty.
What you need to understand is the current situation with both phones. LG still has some really annoying bugs that needs ironing out. Other than that there is really nothing to complain about that phone other than quality control issues LG is having. This phone should NOT be purchased from abroad. Buy it locally as the %age of people having issues with screen is higher than I have seen in recent past. I had to personally exchange / RMA two Optimus 2X to get the piece with perfect screen with no bleeding.
Now coming to the price and warranty. This is at this point in time should not matter to potential buyer. Why you ask? The answer is simple. Both of these phones will be seriously outgunned and outclassed very very soon. SGS II is already here and plethora of new phones will launch before the year ends that will totally outclass both these phones. In the end as said before, the value of these phones will be same with or without warranty down the line due to the fact that Motorola has superior core hardware.
Atrix is overall better built device, does not have any common hardware flaws. And it has just started receiving some serious developer attention.
The more RAM will be huge factor in future updates and ability of this phones to cope with those.
So even if its without warranty and still costing more than 20k, get the new one (unless you get lucky with ebay auctions ) from ebay. And I would personally take Atrix over O2X. Its actually so good that it does not make me miss my SGS II (I know its not as good as SGS II, but you really do get the point of having higher resolution screen and much better battery life if your phone is also your preferred mobile internet device )
