Thanks for the response -
I checked on the apple support page and it did say that the imac has warranty until october. So all should be fine if the buyer would like to extend their applecare protection?
Generally: It should be ok, although technically, AppleCare protection requires that you have the original receipt (read the fine print). I think that as long as the AppleCare is purchased before 1 year from the
manufacturing date, there's no reason for Apple not to honor the extended warranty.
But in your case, since you bought it online directly from Apple, there should be no problem at all, since Apple knows exactly when it was purchased. A copy of the online receipt is proof enough.
Along with a copy of that online receipt, give the new buyer a typed letter transferring ownership of the iMac from you to him/her, sign and date it. Make sure the serial # of the iMac is in the letter. That should be all they ever need if they want to buy their own AppleCare.