not overclock - buy retail
overclock - must buy retail - they don't care if you burn it by overclock or put in microwave, just don't make physical damage or cut the bridge. $15 more for easy to abuse warranty for 3 years - what a deal!
retail advantages:
less chance of buying remarked cpu
3 years easy to abuse warranty
protection box for shipping the cpu to someone else if you'll sell it in the future
installation manual (not a big advantage since amd has put up the manual in pdf format online)
stock HSF is at least better than under $10 aftermarket one
logo sticker
if you want oem, don't look at the warranty, just look at the lowest price one.
15 days, 1 month, or 1 year or even liftetime doesn't matter since it's provided by the seller, not the manufacturer.
if you damage or burn it, do you think the seller will give you a new one generously?
cpu doesn't go bad easily, when it works from the beginning, it'll probably work forever.
that's why some sellers only give only 15 days warranty on oem cpu - they know if it doesn't work at first, it's bad, must replace another one for you.
that's also why some sellers give 1 year warranty - they know if it works at first, it'll work forever.
because of improper installation and improper cooling can damage the cpu easily, some sellers give 1 year warranty if you also buy a HSF from them too, otherwise 15 days.
if you don't intend to buy a better HSF like vantec, globalwin, alpha, etc. those over $20 kind,
don't get oem cpu with cheapy $10 HSF, buy retail.
however, it's still ok to buy oem, must use credit card with purchase protection. in case of damage during installation, let the credit card company eats it if the seller knows it's damaged by you instead of DOA and refuse to give you a new one.